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RESUMEN Objetivos: Determinar la validez y confiabilidad del instrumento “Computer Vision Syndrome Questionnaire (CVS-Q)” en la medición del Síndrome Visual Informático en personal de salud de Lima. Material y métodos: Estudio observacional, descriptivo y de corte transversal, de tipo evaluación de cuestionario, realizado en 82 trabajadores de salud. La validez de contenido se evaluó mediante juicio de expertos con método estadístico de V de Aiken; Validez de constructo, mediante análisis factorial; validez discriminante, a través de la curva operador-receptor (ROC) contrastada con el cuestionario CSSV17; confiabilidad de consistencia interna, con alfa de Cronbach; confiabilidad test - re-test (con 7 días de diferencia); con Rho de Spearman y Coeficiente de Correlación Intraclase (CCI), con intervalos de confianza (IC) del 95%. Se empleó para el procesamiento el software SPSS versión 20.0 para Windows con licencia de prueba. Resultados: El V de Aiken obtuvo un valor de 100%. El análisis factorial extrajo 3 componentes principales que explicaron el 69,455% de la varianza total. El área bajo la curva ROC fue 0,889 [(0,845-0,934); IC=0,95] (p=0,000), sensibilidad 72,22% y especificidad 100%. El alfa de Cronbach fue 0,939, Rho de Spearman 0,884 (p=0,000) y CCI 0,856 [(0,777 - 0,907); IC=0,95] (p=0,000). Conclusiones: El Cuestionario CVS-Q es válido y confiable para ser aplicado sobre el grupo ocupacional de profesionales de la salud con buenas propiedades psicométricas. SUMMARY Objectives: To determine the validity and reliability of the instrument "Computer Vision Syndrome Questionnaire (CVS-Q)" in the measurement of the Computer Visual Syndrome in health personnel in Lima. Methods: A quantitative, observational, descriptive, cross-sectional and questionnaire study was carried out in 82 health workers. Content validity was evaluated by expert judgment with the Aiken V statistical method; construct validity, through factor analysis; discriminant validity, through the receiver operating characteristic curve (ROC) curve contrasted with the CSSV17 questionnaire; internal consistency reliability, with Cronbach's alpha; reliability test - re-test (7 days apart); with Spearman's Rho and Interclass Correlation Coefficient (ICC) with 95% CI. The SPSS software version 20.0 for Windows with a trial license was used for its processing. Results: The V of Aiken obtained a value of 100%. The factor analysis extracted 3 main components that explain 69.455% of the total variance. The area under the ROC curve was 0.889 [(0.845-0,934); CI=0.95] (p=0.000), sensitivity 72.2% and specificity 100%. Cronbach's alpha was 0.939, Spearman's Rho 0.884 (p=0.000) and ICC 0.856 [(0.777 - 0.907); CI=0.95] (p=0.000). Conclusions: The CVS-Q questionnaire is valid and reliable to be applied in the health professionals’ occupational group with good psychometric properties.

Purpose: To assess the prevalence of digital eye strain among children and extrapolate the association between knowledge, attitude, and practice patterns related to device use during the coronavirus disease 2019 (COVID-19) lockdowns. Methods: A cross-sectional, descriptive, questionnaire-based analysis was done to assess the knowledge, attitude, and practice patterns related to digital device use among parents of children attending online classes. Results: A total of 305 responses were obtained. The most common reason for device use was online classes (288 children; 94.4%) and the most common mode was smartphone (263 children; 86.3%). The prevalence of digital eye strain was 64.6%. The mean knowledge score was 48.5 ± 5.1, the mean attitude score was 26.7 ± 4.9, and the mean practice score was 17.8 ± 3.5. The difference between knowledge, attitude, and practice scores among parents of children with and without glasses was not statistically significant ( P = .580, .521, and .503, respectively). A direct correlation was found between the knowledge and practice scores ( P = .002), but attitude scores did not show a significant correlation ( P = .712). Conclusions: Digital devices have been a boon to continue education during the ongoing COVID-19 pandemic. This study reveals a large knowledge gap among parents related to safe digital device use. Further, there is a need to adopt methods that would help spread awareness to the masses about the effects of excessive screen time in children in the form of digital eye strain and myopia and the corrective measures to avoid the same. [ J Pediatr Ophthalmol Strabismus . 2022;59(4):224–235.]

In optical see-through augmented reality (AR), information is often distributed between real and virtual contexts, and often appears at different distances from the user. To integrate information, users must repeatedly switch context and change focal distance. If the user's task is conducted under time pressure, they may attempt to integrate information while their eye is still changing focal distance, a phenomenon we term transient focal blur. Previously, Gabbard, Mehra, and Swan (2018) examined these issues, using a text-based visual search task on a one-eye optical see-through AR display. This paper reports an experiment that partially replicates and extends this task on a custom-built AR Haploscope. The experiment examined the effects of context switching, focal switching distance, binocular and monocular viewing, and transient focal blur on task performance and eye fatigue. Context switching increased eye fatigue but did not decrease performance. Increasing focal switching distance increased eye fatigue and decreased performance. Monocular viewing also increased eye fatigue and decreased performance. The transient focal blur effect resulted in additional performance decrements, and is an addition to knowledge about AR user interface design issues.

To explore the intervention effect of traditional Chinese medicine hot pressing combined with health education in adolescents with asthenopia, 92 adolescents with asthenopia admitted to the outpatient department of Guangming Traditional Chinese Medicine Hospital in Pudong New Area from October 2019 to January 2021 were selected and randomly divided into two groups: the control group and the test group, each with 46 cases. Both received health education. The control group was given sodium hyaluronate eye drops, and the test group was given traditional Chinese medicine hot ironing technique intervention. After 2 courses of treatment, the scores of visual fatigue symptoms, clinical curative effect, and eye refractive power of the two groups were observed. The satisfaction of treatment was compared between the two groups. The scores of asthenopia of the two groups were compared at 6 months after intervention. After the intervention, the scores of visual fatigue symptoms in the control group and the test group were reduced after one or two courses of treatment (control group: t = 4.167, 6.318, and P = 0.027 , 0.010; test group: t = 4.820, 6.834, and P = 0.013 , P < 0.05 ; the total clinical effective rate of the trial group was 93.48%, which was significantly higher than that of the control group (80.43%). The difference between the groups was statistically significant P < 0.05 ; the left and right eyes of the control group did not change significantly before and after the intervention P > 0.05 . After the intervention, the left and right eyes of the paper group were significantly reduced P < 0.05 . After the intervention, the difference of the two groups in the refractive power of the left and right eyes was statistically significant P < 0.05 . After treatment, the satisfaction of the experimental group was significantly higher than that of the control group P < 0.05 . After 6 months, there was no significant change in the visual fatigue score of the experimental group, while the visual fatigue score of the control group increased significantly. The traditional Chinese medicine ironing combined with health education intervention can improve the symptoms of adolescents’ asthenopia and improve the treatment efficiency. The method is safe, and the operation is convenient. It is worthy of clinical promotion.

This paper aims to investigate the efficacy of circularly polarized light smartphones in affecting dry eye symptoms and asthenopia through a comparison with linearly polarized smartphones. One hundred twenty participants were randomly divided into four groups. Dry eye and asthenopia symptoms were evaluated using the Ocular Surface Disease Index (OSDI), Computer Vision Syndrome Scale 17 (CVSS17), Convergence Insufficiency Symptom Survey (CISS), and visual analogue scale (VAS). Objective ocular examinations were assessed by confusion flicker frequency (CFF), tear meniscus height (TMH), noninvasive break-up time (NIBUT), conjunctiva redness, fluorescein tear break-up time (FTBUT), corneal fluorescein staining, and the Schirmer I test. Tests were performed before and after a reading task. Subjective evaluations including the OSDI, CVSS17, and CISS were all significantly increased after reading on a linearly polarized smartphone, whereas no change was observed in the circular polarization groups in both light and dark environments. A significantly enlarged VAS was shown in all of the four groups, but a significant increase in ΔVAS only appeared in the linear polarization groups. There were significant decreases in TMH, NIBUT, conjunctiva redness, FTBUT, and CFF after reading on a linearly polarized smartphone but the circularly polarized smartphone had lesser effects on these parameters. Our study indicated that reading on linearly polarized smartphones may cause dry eye disorder, asthenopia, and ocular discomforts, whereas circularly polarized smartphones appears to minimize these adverse effects on eye dryness and visual fatigue in light and dark environments.

Introduction Symptoms experienced when using digital devices are known as digital eyestrain (DES) or computer vision syndrome. They can be categorised as either external (associated with dry eye) or internal (related to refractive, accommodative or binocular vision anomalies). In a large cohort of adults with DES, we investigate the prevalence of binocular and accommodative anomalies, contrasting different diagnostic approaches, to evaluate potential mechanisms for the benefit from +0.75D addition lens that has been previously reported. Methods Participants (20−40y) were selected using the Computer Vision Syndrome Questionnaire (CVS-Q) tool as suffering with DES. A comprehensive eye examination was given to each participant, and this paper concentrates on “internal factors”, detected with a refraction and comprehensive testing of binocular and accommodative functions. The effects of low-powered addition lenses (+0.50D, +0.75D, +1.25D; and plano controls) were assessed by double-masked testing with the Wilkins Rate of Reading Test (WRRT) and by subjective preference. Results As previously reported, most participants showed a subjective preference for one of the three convex lenses we used, with +0.75D chosen most frequently. Performance at the WRRT was significantly improved with +0.50D and +0.75D, but not +1.25D. Using a variety of diagnostic criteria, there were no strong associations between WRRT results or CVS-Q scores and any binocular or accommodation functions. The one finding of significance is that a disproportionate number of participants who benefited from adds had an eso-fixation disparity on the near Mallett unit, although this only affected 5% of the population. Conclusions DES is a collection of diverse symptoms that have a multifactorial aetiology. In the sample described here, binocular and accommodative anomalies do not seem to be a major cause of DES. Nevertheless, in view of the multifactorial aetiology it is recommended that patients with the symptoms of DES are assessed with a comprehensive eye examination. Patients with an esophoric fixation disparity on the near Mallett unit are particularly likely to benefit from near additions.

BACKGROUND: Social distancing was implemented worldwide due to the coronavirus (COVID-19) pandemic. This impacted physical activity levels and increased the time spent in sedentary behaviors which may contributed to the emergence of increased musculoskeletal complaints. OBJECTIVE: To assess the consequences of social distancing for the increase in perceived pain of students and professors from higher education institutions. METHODS: One thousand two hundred and fifty-four participants responded to an online survey containing sociodemographic information and questions related to daily habits, physical activity profile, and musculoskeletal pain before and during the pandemic. Levels of concentration, nervousness, productivity, and visual fatigue were also assessed. The primary outcome was presence of perceived pain before and during the pandemic, dichotomized between those with and without increased pain during the pandemic. RESULTS: Perceived pain increased during the pandemic (p 6 hours (p = 0.041; PR = 1.44; 95% CI = 1.02–2.06). Nervousness (p = 0.001) and visual fatigue (p = 0.001) increased, whereas concentration (p = 0.001) and productivity (p = 0.001) reduced during the pandemic. CONCLUSIONS: Reduced physical activity practice and increased time in sedentary behavior and electronic device usage during the pandemic were associated with increased musculoskeletal pain in students and professors from higher education institutions. Decreased concentration and productivity and increased nervousness and visual fatigue were also observed during the pandemic.

IntroductionDigital eye strain, which is often ignored by the public, has emerged as a “Shadow Pandemic” in the era of the COVID-19 pandemic.AimThe current paper is aimed at discussing the ill effect of digital screens on eyes in the wake of the COVID-19 pandemic.MethodologyA literature search was done using “PubMed,” “Google scholar”, and “Scopus” using key terms like “Digital Eye Strain,” “Eyestrain,” or “Computer Vision Syndrome.” Relevant articles were identified and included to support the argument for this narrative review.ResultsStudies conducted in the UK reported that 68% of children extensively use computers, while 54% undertake online activities after the age of 3. Similar studies estimated 4 h and 45 min per day of screen exposure time among adults in the UK. Indian studies reveal that the prevalence of DES is 69% in adults and 50% in children respectively. Indian ophthalmologists found that computer-using and specialized ophthalmologists were more informed of symptoms and diagnostic signs but were misinformed about treatment modalities. The use of social media and multitasking is particularly prominent among younger adults, with 87% of individuals aged 20–29 years reporting the use of two or more digital devices simultaneously. It has been observed that the use of computer glasses corrects refractive errors and helps in the reduction of symptoms, while precision spectral filters help in reducing symptoms of micro-fluctuation of accommodation.ConclusionWe concluded that DES is emerging globally as a “Shadow Pandemic” and it is high time to respond. Community ophthalmologists, public health authorities, and educational sectors especially should be involved to prevent this.

Intelligent mines require much more mental effort from visual display terminal (VDT) operators. Long periods of mental effort can easily result in operator fatigue, which further increases the possibility of operation error. Therefore, research into how brain fatigue affects the sustained attention of VDT operators in intelligent mines is important. The research methods were as follows: (1) Recruit 17 intelligent mine VDT operators as subjects. Select objective physiological indicators, such as reaction time, error rate, task duration, flicker fusion frequency, heart rate, electrodermal activity, and blink frequency, and combine these with the subjective Karolinska Sleepiness Scale to build a comprehensive brain fatigue evaluation system. (2) According to the fatigue-inducing experiment requirements, subjects are required to carry out mathematical operations in accordance with the rules during the presentation time, determine whether the results of the operations fall within the [7, 13] interval, and continue for 120 min to induce brain fatigue. (3) Perform the standard stimulus button response experiment of the sustained attention to response task, before and after brain fatigue, and compare each result. The results show that: (1) When the standard stimulus appeared in the EEG experiment, the amplitude of the early N100 component before and after brain fatigue was significantly different. When the bias stimulus appeared, the average amplitudes of the P200 component and the late positive component, before and after brain fatigue, were significantly different, suggesting that the brain fatigue of VDT workers in coal mines would reduce sustained attention; (2) After the 120 min of the continuous operation task, the subjects showed obvious brain fatigue. The objective brain fatigue was followed by an increase in reaction time, an increase in error rate, a decrease in flicker fusion frequency, an increase in heart rate, an increase in electrodermal current, an increase in the number of blinks, and a larger pupil diameter, and both the subjective and objective data indicated more significant changes in the subjects’ brain fatigue at the 45th and 90th min. The results of the study could provide insight into the reduction in operational efficiency and safety of VDT operators in intelligent mines due to brain fatigue and further enrich the research in the area of brain fatigue in VDT operations.

Purpose To investigate if blue-blocking lenses are effective in reducing the ocular signs and symptoms of eye strain associated with computer use. Design Double-masked, randomized controlled trial. Methods A total of 120 symptomatic computer users were randomly assigned (1:1) into a “positive” or “negative” advocacy arm (ie, a clinician either advocating or not advocating for the intervention via a prerecorded video). Participants were further sub-randomized (1:1) to receive either clear (placebo) or blue-blocking spectacles. All participants were led to believe they had received an active intervention. Participants performed a 2-hour computer task while wearing their assigned spectacle intervention. The prespecified primary outcome measures were the mean change (post- minus pre-computer task) in eye strain symptom score and critical flicker-fusion frequency (CFF, an objective measure of eye strain). The study also investigated whether clinician advocacy of the intervention (in a positive or negative light) modulated clinical outcomes. Results All participants completed the study. In the primary analysis, for CFF, no significant effect was found for advocacy type (positive or negative, p = .164) and spectacle intervention type (blue-blocking or clear lens, p = .304). Likewise, for eye strain symptom score, no differences were found for advocacy (p = .410) or spectacle lens types (p = .394). No adverse events were documented. Conclusions Blue-blocking lenses did not alter signs or symptoms of eye strain with computer use relative to standard clear lenses. Clinician advocacy type had no bearing on clinical outcomes.

To compare the clinical efficacy betweenForty-six cases (92 eyes) with presbyopia complicated with visual fatigue of liver depression and spleen deficiency were randomly divided into an observation group (23 cases) and a control group (23 cases, 2 cases dropped off). The cases in the observation group were treated withCompared before treatment, the visual fatigue core symptoms scores in the two groups were decreased after 1-week and 2-week treatment (

Objectives Advances in dental operative microscopes (DOMs) enable examination of root canal morphology or detection of root fractures otherwise not visible to the naked eye. However, dental therapy involving prolonged use of DOMs requires precision within a limited visual field, resulting in eye strain among users. This study examined the effects of halogen and light-emitting diode (LED) light sources on asthenopia and visual function following use of DOMs. Methods The study used halogen and LED light sources in DOMs. The first experiment was conducted on 6 participants with corrected visual acuity without any organic eye disease. General visual function test (calculation ability test, hand grip strength test, and ophthalmic examination) and subjective symptom questionnaire were used to evaluate the degree of fatigue before and after DOM use. The second experiment was conducted on 9 participants with spherical equivalents within ±4 diopters (D) and astigmatism of 1 D or less. Accommodative function tests (precise test for asthenopia) and a subjective symptom questionnaire (asthenopia) were used before and after use of DOM. Results No significant changes were noted in the degree of fatigue and ophthalmological parameters before and after the procedure with either light source or in between light sources. The tear firm breakup time was shortened after therapy, and a tendency toward dry eyes was observed while using the LED light source. Conclusions The halogen and LED light sources used for DOM therapy had similar effects on asthenopia of the operators, with no significant changes in visual function.

Purpose To investigate the effects of watching ultra-high-definition television (UHD TV) on subjective ocular fatigue and objective ocular surface indices. Methods A total of 76 volunteers were recruited for this study. Subjects watched UHD TV for 10 minutes at a viewing distance of 110 cm. Best-corrected visual acuity, refractive errors, tear break-up time, corneal staining grading, conjunctival redness grading by slit-lamp examination, tear meniscus measurement by anterior segment optical coherence tomography, and ocular symptom scores were obtained before and immediately after watching UHD TV. Subgroup analyses were conducted according to participant age (old age group >50 years vs. young age group ≤50 years) and dry-eye syndrome (presence vs. absence). The relationship between subjective and objective indices was evaluated. Results The mean age of subjects was 39.6 ± 12.4 years. Watching UHD TV induced a decrease in tear break-up time in the non-dry-eye group (p < 0.001) but not in the dry-eye group (p = 0.726). Corneal staining grades increased in all subgroups, and the changes were particularly larger in the older group (p = 0.038). The increase in ocular symptom scores was larger in the dry-eye group (p = 0.08) and in the older group (p = 0.016). The decrease in tear break-up time and ocular symptom scores after watching UHD TV was significantly correlated with tear break-up time. Conclusions Tear break-up time significantly decreased in non-dry-eye subjects after watching UHD TV. Subjective ocular discomfort increased significantly in subjects over the age of 50 and in participants with dry-eye syndrome.

Background: Three-dimensional (3D) laparoscopic surgery in pediatrics is still uncommon and few studies assessed in clinical practice advantages and disadvantages. Applicability and effectiveness o...

Background Many ophthalmic lens manufacturers are currently marketing blue-blocking filters, which they claim will reduce symptoms of Digital Eye Strain (DES). However, there is limited evidence to support the proposal that DES results from the blue light emitted by electronic screens. Objective This investigation compared the effect of blue-blocking filters on DES symptoms with a no-filter lens, using a double-blind methodology. Methods Twenty-four subjects were required to perform a 20-minute reading task from a tablet computer. They wore either lenses containing a blue-blocking filter (TheraBlue 1.67 or TheraBlue polycarbonate) or a CR-39 control lens which did not include a filter. Immediately following each session, subjects completed a questionnaire to quantify symptoms of DES. Results While a significant increase in symptoms was observed immediately following the near vision task (p = 0.00001), no significant difference in symptoms was found between the 3 lens conditions (p = 0.74). Conclusions There is little evidence at this time to support the use of blue-blocking filters as a clinical treatment for DES. Management of other ocular factors, as well as the creation of an optimal environment for screen viewing, are more likely to provide greater success in minimizing symptoms.

Blur is the subjective awareness that the edges of a high contrast image are indistinct. The concept of blur is fundamental to the understanding of vision, accommodation, refractive error, concomitant strabismus, and asthenopia. It is easy for clinicians to believe that blur always needs to be avoided or resolved, or that everyone responds to blur similarly. This narrative review outlines the literature on blur and the accommodation to resolve it, and relates it to current clinical practice. Laboratory studies have traditionally been highly controlled, using expert observers, but more recent research using naïve participants suggests that variability and tolerance of blur are common and more widespread than often thought, especially in children and clinical groups. Objective and subjective responses can differ widely, and it cannot be assumed that because we expect accommodation to have occurred, that it always has. A deeper understanding of the role of blur and objective accommodation in vision, refractive error and strabismus may help us understand the variability that exists in clinical practice. We may use blur to help investigation and treatment but also be relaxed about what is normal. Many patients are led to believe that they should always achieve constant clear vision, when this is unrealistic. Although pathological blur must be identified and treated, normal everyday blur may become medicalized into "a problem" by well-meaning professionals.

Stereoscopic viewing has an impact on ocular dynamics, but its effects on accommodative functions are not fully understood, especially for autostereoscopic viewing. This study aimed to investigate the changes in dynamic accommodative response, accommodative amplitude, and accommodative facility of myopes after autostereoscopic visual training.We enrolled 46 adults (men = 22 and women = 24; age = 21.5 ± 2.5 [range = 18-25] years, spherical equivalent: -4.52 ± 1.89 [-8.88 to -1.75] diopters [D]) who visited the EyeENT Hospital of Fudan University. The study population was randomly divided into three-dimensional (3D) and two-dimensional (2D) viewing groups to watch an 11-minute training video displayed in 3D or 2D mode. Dynamic accommodative response, accommodative facility, and accommodative amplitude were measured before, during, and immediately after the training. Accommodative lag and the variability of accommodation were also analyzed. Visual fatigue was evaluated subjectively using a questionnaire.Accommodative lag decreased from 0.54 ± 0.29 D to 0.42 ± 0.32 D (P = 0.004), whereas accommodative facility increased from 10.83 ± 4.55 cycles per minute (cpm) to 13.15 ± 5.25 cpm (P0.001) in the 3D group. In the 2D group, there was no significant change in the accommodative lag (P = 0.163) or facility (P = 0.975), but a decrease in accommodative amplitude was observed (from 13.88 ± 3.17 D to 12.71 ± 2.23 D, P = 0.013). In the 3D group, the accommodative response changed with the simulated target distance. Visual fatigue was relatively mild in both groups.The immediate impact of autostereoscopic training included a decrease in the accommodative lag and an increase in the accommodative facility. However, the long-term effects of autostereoscopic training require further exploration.

Although the high prevalence of digital eyestrain has been well established, to date, there is no objective measurement of this condition. Previous studies have suggested that digital eyestrain may be associated with decreased critical fusion frequency, but the published evidence to support this association is sparse.This study sought to determine whether symptoms of digital eyestrain after a sustained computer task are indeed associated with changes in critical fusion frequency.The experiment was performed on 30 young visual-normal subjects. They attended two sessions, during which they undertook a 20-minute reading task. This comprised either reading random words from a tablet computer or a story from a printed children's book. Critical fusion frequency was measured both before and immediately after each of the reading tasks. In addition, the level of digital eyestrain was assessed by subjects completing a questionnaire regarding ocular and visual symptoms experienced during each of the reading trials.The mean increase in digital eyestrain symptoms after the digital and printed conditions was 11.37 (standard error of the mean [SEM], 2.23) and 4.40 (SEM, 1.34), respectively. Both the post-task symptom change (P.001) and the difference between the two reading conditions (P = .004) were significant. The mean change in critical fusion frequency after the digital and printed conditions was -0.42 (SEM, 0.25) and -0.72 (SEM, 0.26), respectively. Neither the post-task change nor the difference between the two reading conditions was significant. In addition, when considering the digital condition only, no significant correlation was observed between the changes in critical fusion frequency and reported symptoms.These results do not support the proposal that changes in critical fusion frequency can be used as an objective measure of eyestrain or other symptoms of digital eyestrain.

Purposes: This study discussed the accommodative response and pupil size of myopic adults using a double-mirror system (DMS). The viewing distance could be extended to 2.285 m by using a DMS, which resulted in a reduction and increase in the accommodative response and pupil size, respectively. By using a DMS, the reduction of the accommodative response could improve eye fatigue with near work. Method: Sixty subjects aged between 18 and 22 years old were recruited in this study, and the average age was 20.67 ± 1.09. There were two main steps in the experimental process. In the first step, we examined the subjects’ refraction state and visual function, and then fitted disposable contact lenses with a corresponding refractive error. In the second step, the subjects gazed at an object from a viewing distance of 0.4 m and at a virtual image through a DMS, respectively, and the accommodative response and pupil size were measured using an open field autorefractor. Results: When the subjects gazed at the object from a distance of 0.4 m, or gazed at the virtual image through a DMS, the mean value of the accommodative response was 1.74 ± 0.43 or 0.16 ± 0.47 D, and the pupil size was 3.98 ± 0.06 mm or 4.18 ± 0.58 mm, respectively. With an increase in the viewing distance from 0.4 m to 2.285 m, the accommodative response and pupil size were significantly reduced about 1.58 D and enlarged about 0.2 mm, respectively. For three asterisk targets of different sizes (1 cm × 1 cm, 2 cm × 2 cm, and 3 cm × 3 cm), the mean accommodative response and pupil size through the DMS was 0.19 ± 0.16, 0.27 ± 0.24, 0.26 ± 0.19 D; and 4.20 ± 1.02, 3.94 ± 0.73, 4.21 ± 0.57 mm, respectively. The changes of the accommodative response and pupil size were not significant with the size of the targets (p > 0.05). In the low or high myopia group, the accommodative response of 0.4 m and 2.285 m was 1.68 ± 0.42 D and 0.21 ± 0.48 D; and 1.88 ± 0.25 D and 0.05 ± 0.40 D, respectively. The accommodative response was significantly reduced by 1.47 D and 1.83 D for these two groups. The accommodative microfluctuations (AMFs) were stable when a DMS was used; on the contrary, the AMFs were unstable at a viewing distance of 0.4 m. Conclusions: In this study, the imaging through a DMS extended the viewing distance and enlarged the image, and resulted in a reduction in the accommodative response and an increase in the pupil size. For the low myopia group and the high myopia group, the accommodative response and pupil size were statistically significantly different before and after the use of the DMS. The reduction of the accommodative response could be applied for the improvement of asthenopia.

Background. To validate the 17-item Computer Vision Symptom Scale questionnaire (CVSS17) in Italian. Methods. Cross-sectional validation study on video terminal (VDT) users and a reference sample of subjects not working at a VDT (control group), cognitively able to respond to a health status interview. The Italian self-administered version of the CVSS17 questionnaire was administered to all participants. The reliability and validity of the Italian translation of the CVSS17 were tested using standard statistical methods for questionnaire validation. The Rasch analysis was performed as well. Results. A total of 216 subjects were enrolled. Concerning the reliability, the Cronbach’s alpha coefficient was 0.925 (from 0.917 to 0.924), and the test–retest stability was 0.91 (

Objetivo: Analizar la prevalencia y la evolución del síndrome visual informático en estudiantes de secundaria y bachillerato mediante el CVS-Q© adaptado y validado para adolescentes, según empleen libros en papel o en soporte digital. Método: Se adaptará el CVS-Q© mediante un pilotaje en adolescentes y un grupo nominal compuesto por especialistas en salud visual, profesorado y padres/madres. Se evaluarán la calidad y la aplicabilidad de la versión resultante (CVS-Q teen©) y se realizará un estudio de validación con pruebas visuales, retest y análisis psicométrico. Posteriormente, se realizará un estudio prospectivo longitudinal con cuatro medidas repetidas en adolescentes de dos institutos de San Juan de Alicante (uno ha sustituido libros por tabletas). Se medirá el síndrome visual informático mediante el CVS-Q teen© con tres seguimientos. Se analizará la prevalencia de síndrome visual informático según factores sociodemográficos, visuales y de uso de dispositivos digitales. Se realizarán modelos de regresión logística con efecto aleatorio por estudiante y tiempo de uso. Objective: To analyse the prevalence and progression of computer vision syndrome in secondary and high school students with the CVS-Q© adapted and validated for adolescents, depending on whether they use textbooks or digital books. Method: The CVS-Q© will be adapted by a pilot study in adolescents and a nominal group of visual health specialists, teachers and parents. The resulting version (CVS-Q teen©) will be tested to confirm its quality and applicability and a validation study will be done with visual tests, retest and psychometric analysis. Subsequently, a prospective longitudinal study with four repeated measures will be carried out in adolescents from two secondary schools of San Juan de Alicante (one has replaced textbooks by tablets). Computer vision syndrome will be measured by the CVS-Q teen© with three follow-ups. The prevalence of computer vision syndrome will be analysed according to sociodemographic, visual and digital device use variables. Logistic regression models will be performed, with random effect by student and time of use. Los autores agradecen al Vicerrectorado de Investigación de la Universidad de Alicante por el contrato de formación predoctoral de la segunda autora (UAFPU2019-08). El presente proyecto ha sido financiado por la convocatoria «Proyectos de Investigación en Salud», Fondo de Investigación en Salud del Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación y Unión Europea, a través de los Fondos Europeos de Desarrollo Regional (FEDER) «Una manera de hacer Europa», con la referencia PI20/01629.

Steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI) systems suffer from low SSVEP response intensity and visual fatigue, resulting in lower accuracy when operating the system for continuous commands, such as an electric wheelchair control. This study proposes two SSVEP improvements to create a practical BCI for communication and control in disabled people. The first is flicker pattern modification for increasing SSVEP response through mixing (1) fundamental and first harmonic frequencies, and (2) two fundamental frequencies for an additional number of commands. The second method utilizes a quick response (QR) code for visual stimulus patterns to increase the SSVEP response and reduce visual fatigue. Eight different stimulus patterns from three flickering frequencies (7, 13, and 17 Hz) were presented to twelve participants for the test and score levels of visual fatigue. Two popular SSVEP methods, i.e., power spectral density (PSD) with Welch periodogram and canonical correlation analysis (CCA) with overlapping sliding window, are used to detect SSVEP intensity and response, compared to the checkerboard pattern. The results suggest that the QR code patterns can yield higher accuracy than checkerboard patterns for both PSD and CCA methods. Moreover, a QR code pattern with low frequency can reduce visual fatigue; however, visual fatigue can be easily affected by high flickering frequency. The findings can be used in the future to implement a real-time, SSVEP-based BCI for verifying user and system performance in actual environments.

This study evaluates the progression of visual fatigue induced by visual display terminal (VDT) using automatically detected blink features. A total of 23 subjects were recruited to participate in a VDT task, during which they were required to watch a 120-min video on a laptop and answer a questionnaire every 30 min. Face video recordings were captured by a camera. The blinking and incomplete blinking images were recognized by automatic detection of the parameters of the eyes. Then, the blink features were extracted including blink number (BN), mean blink interval (Mean_BI), mean blink duration (Mean_BD), group blink number (GBN), mean group blink interval (Mean_GBI), incomplete blink number (IBN), and mean incomplete blink interval (Mean_IBI). The results showed that BN and GBN increased significantly, and that Mean_BI and Mean_GBI decreased significantly over time. Mean_BD and Mean_IBI increased and IBN decreased significantly only in the last 30 min. The blink features automatically detected in this study can be used to evaluate the progression of visual fatigue.

To evaluate the efficacy and safety of interventions for treating eye strain related to computer use relative to placebo or no treatment.Computer use is pervasive and often associated with eye strain, referred to as computer vision syndrome (CVS). Currently, no clinical guidelines exist to help practitioners provide evidence-based advice about CVS treatments, many of which are marketed directly to patients. This systematic review and meta-analysis was designed to help inform best practice for eye care providers.Eligible randomized controlled trials (RCTs) were identified in Ovid MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, and trial registries, searched from inception through November 23, 2021. Eligible studies were appraised for risk of bias and were synthesized. The certainty of the body of evidence was judged using the Grading of Recommendations, Assessment, Development, and Evaluation system. Standardized mean differences (SMDs) were used when differently scaled measures were combined.Forty-five RCTs, involving 4497 participants, were included. Multifocal lenses did not improve visual fatigue scores compared with single-vision lenses (3 RCTs; SMD, 0.11; 95% confidence interval [CI], -0.14 to 0.37; P = 0.38). Visual fatigue symptoms were not reduced by blue-blocking spectacles (3 RCTs), with evidence judged of low certainty. Relative to placebo, oral berry extract supplementation did not improve visual fatigue (7 RCTs; SMD, -0.27; 95% CI, -0.70 to 0.16; P = 0.22) or dry eye symptoms (4 RCTs; SMD, -0.10; 95% CI, -0.54 to 0.33; P = 0.65). Likewise, berry extract supplementation had no significant effects on critical flicker-fusion frequency (CFF) or accommodative amplitude. Oral omega-3 supplementation for 45 days to 3 months improved dry eye symptoms (2 RCTs; mean difference [MD], -3.36; 95% CI, -3.63 to -3.10 on an 18 unit scale; P0.00001) relative to placebo. Oral carotenoid supplementation improved CFF (2 RCTs; MD, 1.55 Hz; 95% CI, 0.42 to 2.67 Hz; P = 0.007) relative to placebo, although the clinical significance of this finding is unclear.We did not identify high-certainty evidence supporting the use of any of the therapies analyzed. Low-certainty evidence suggested that oral omega-3 supplementation reduces dry eye symptoms in symptomatic computer users.

A widely used paradigm for Brain-Computer Interfaces (BCI) is based on detecting P300 Event-Related Potentials (ERPs) in response to stimulation and concentration tasks. An open challenge corresponds to maximizing the performance of a BCI by considering artifacts arising from the user's cognitive and physical conditions during task execution.In this study, an analysis of the performance of a visual BCI-P300 system was performed under the metrics of Sensitivity (Sen), Specificity (Spe), Accuracy (Acc), and Area-Under the ROC Curve (AUC), considering the main reported factors affecting the neurophysiological behavior of the P300 signal: Concentration Level, Eye Fatigue, and Coffee Consumption.We compared the performance of three P300 signal detection methods (MA-LDA, CCA-RLR, and MA+CCA-RLR) using a public database (GigaScience) in different groups. Data were segmented according to three factors of interest: high and low levels of concentration, high and low eye fatigue, and coffee consumption at different times.The results showed a significant improvement between 3% and 6% for the metrics evaluated for identifying the P300 signal in relation to concentration levels and coffee consumption.P300 signal can be influenced by physical and mental factors during the execution of ERPs evocation tasks, which could be controlled to maximize the interface's capacity to detect the individual's intention.

The effect of small anisometropia on visual fatigue when using virtual reality (VR) devices was investigated. Participants (n = 34) visited three times. In the first visit, VR exposure (10 min) was conducted with the full correction of the refractive error of both eyes. Experimental anisometropia was induced by adding a + 1.0 dioptre spherical lens either on the dominant eyes in the second visit or on the non-dominant eyes in the third visit. At each visit, the participants played a predetermined video game using a head-mounted display VR for 10 min. Visual fatigue was assessed before and after playing VR game using the Virtual Reality Symptom Questionnaire (VRSQ) and high-frequency component of accommodative microfluctuation. Results showed that watching VR induced significant increase of VRSQ score, significant decrease in the maximum accommodation power and objective increase in visual fatigue. Experimental anisometropia induction either on the dominant or non-dominant eyes did not aggravate visual fatigue. Practitioner summary: Mild differences in refractive error (up to 1.0 dioptre) between both eyes do not significantly increase ocular fatigue by viewing virtual reality device (10 min). The impact of small anisometropia may be limited in developing a virtual reality device. Abbreviations: VR: virtual reality; VRSQ: virtual reality symptom questionnaire; HMD: head-mounted display; HFC: high-frequency component.

Esports is gaining acceptance in the world of professional, collegiate, and high school athletics. However, there is a lack of information for osteopathic physicians about the health concerns and appropriate treatment of esports athletes. Because of the sedentary nature of the sport and accompanying poor posture, esports athletes are likely to have musculoskeletal injuries of the neck, back, and upper extremities. Additionally, these athletes may have metabolic disturbances resulting from light-emitting diode computer monitors as well as mental health concerns regarding gaming addiction and social behavior disorders. The authors explore the osteopathic physician's role in promoting health and reducing injury in this new gaming phenomenon.

Computer vision syndrome is common and affects performance of visual tasks. Background illumination, light source, light compensation, position of the display, contrast and glare are environmental factors associated with computer vision syndrome. The aim of this study is to investigate the effects of reflected glare and visual field lighting on computer vision syndrome.In a reflected glare experiment, participants performed a two-hour visual task using a glossy, matte, or glare-free surface display in two visual environments (normal, glare). In a visual field lighting experiment, participants performed the visual task in dim lighting, uneven supplementary lighting, or uniform supplementary lighting. Visual function parameters, including critical fusion frequency, heterophoria, amplitude of accommodation and accommodative facility were evaluated by the investigators and a visual fatigue questionnaire was completed before and after the visual task. Visual performance was also recorded. In addition, the variation of pupil size under different lighting conditions was analysed.Critical fusion frequency was the only visual function parameter which decreased significantly after the visual task. The questionnaire score was significantly higher in a glare environment and was lower when the task was performed using a glare-free display. Visual performance was significantly worse in the glossy display group. The increment in the questionnaire score was smaller in the uniform supplementary lighting group. Visual performance was significantly worse in the dim lighting or uneven supplementary lighting group, but not in the uniform supplementary lighting group. Variation in pupil size was significantly greater in the dim lighting condition than in the supplementary lighting condition.Critical fusion frequency is an effective indicator of computer vision syndrome. Glare-free displays could alleviate visual fatigue and preserve visual performance. Uniform supplementary lighting could decrease variation in pupil size and prevent eye strain.

SIGNIFICANCE The present study addresses the accommodative response and its dependence on the type of optical correction used. The results are discussed relative to their possible implications for myopia progression and visual fatigue. PURPOSE The accommodative response has been investigated owing to its possible relationship with the onset and progression of myopia and visual fatigue. This study explored the influence of wearing soft contact lenses in comparison with spectacles in terms of magnitude and variability of accommodation. In addition, we analyzed the intersession and intermethod repeatability. METHODS Dynamic accommodative response was recorded during 30-second epochs, at five different distances (50, 40, 33, 25, and 20 cm), in 21 individuals (mean refractive error ± SD, -0.79 ± 1.39 D) while wearing either soft contact lenses or spectacles on two different days. To assess repeatability, a second identical intervention was conducted. RESULTS Higher lags of accommodation were obtained with the use of soft contact lenses in comparison with the spectacle condition (P =.04, partial η 2 [η p 2] = 0.204), and similarly, a higher variability of accommodation at near distances was found during the soft contact lens measurement (P

The authors consider presented in the literature tested new approaches to diagnosis, prevention and correction of symptoms of asthenopia in persons visually-intense work related to theoretical aspects of asthenopia in fact, the selection of spectacle correction and application of a multidisciplinary approach. Determines the pattern of allocation in the traditional classification of asthenopia (accommodative, muscular, sensory) classification criterion is the presence or absence of phenomena of psychological maladjustment. Along with this, it is established that the astigmatic component correction of complex myopic astigmatism, it is advisable to perform in the range of 60–75 % of the required (according to cycloplegics examination of refraction). At the same time, the level of visual performance (in the most difficult conditions of presentation of test information of the type “choice of signal from several — evaluation of the signal — response ratio”) with incomplete (60–75 %) correction by 12.7–20.4 % (p < 0.05) is higher than with partial (75–85 %) and complete, taking into account minor differences in the achieved visual acuity (0.04–0.08, p > 0.05). In addition, the practical expediency of applying a multidisciplinary approach to the correction of asthenopia, based on the complex effects of specific and non-specific methods of stimulation of vision. It was found that the combined use of multidirectional technologies of physical impact (low-energy laser radiation, cranial osteopathic effects and special training of the cervical-thoracic spine) provides effective correction of accommodation disorders, which is confirmed by a pronounced, statistically significant positive dynamics of clinical and functional, ophthalmic-ergonomic and subjective indicators of the visual system after a course of therapeutic and restorative measures.

Eye fatigue is a common health problem across all age groups. Herein, we explored the correlation between eye fatigue and thickness of the retinal nerve fiber layer (NFL). Included in the NFL are intrinsically photosensitive retinal ganglion cells (ipRGCs), which are associated with trigeminal pain. This retrospective cross-sectional study included outpatients with best-corrected visual acuity above 20/30 in both eyes and without dry eye, glaucoma, or retinal disease. A total of 1981 patients were initially enrolled and 377 patients were declared as eligible for the study analysis. We tested subjects for the presence of major ocular symptoms and measured thickness of ganglion cell complex (GCC) using optical coherence tomography. A total of 377 outpatients (46.4% men, mean age of 57.1 years) were enrolled for analysis, based on the interview-reported prevalence of six eye symptom, as follows: 31.5% for eye fatigue, 19.2% for blurring, 18.6% for dryness, 15.7% for photophobia, 13.5% for irritation, and 4.6% for pain. The macular GCC was significantly thicker in subjects with eye fatigue compared to the group not reporting eye fatigue (103.8 μm versus 100.3 μm, P = 0.014). Regression analysis identified eye fatigue (P = 0.026, β=0.122, adjusted for age and sex) and dryness (P =0.024, β=0.130) as significantly correlated with the macular GCC thickness, while the full macular thickness showed no significant correlation. In conclusions, eye fatigue and dryness were positively associated with thickness of the macular GCC. Nonvisual symptoms might therefore play a role in the development of eye fatigue.

Objective. The introduction of advanced endoscopic systems, such as the Storz Image1S and the Olympus Endoeye, heralds a new era of 3-dimensional (3D) visualization. The aim of this report is to provide a comprehensive overview of the neurophysiology of 3D view, its relevance in videoscopy, and to quantify the benefit of the new 3D technologies for both rigid and articulated instruments. Method. Sixteen medical students without any laparoscopic experience were trained each for a total of 27 hours. Proficiency scores were determined for rigid and articulated instruments under 2D and 3D visualization conditions. Results. A reduction in execution time of 14%, 28%, and 36% was seen for the rigid instruments, the da Vinci, and Steerable instruments, respectively. A reduction in errors of 84%, 92%, and 87% was seen for the rigid instruments, the da Vinci, and Steerable instruments, respectively. Conclusion. 3D visualization greatly augments endoscopic procedures. The advanced endoscopic systems employed in the recent study caused no visual fatigue or discomfort. The benefit of 3D was most distinct with articulated instruments.

Many manufacturers are currently marketing blue-blocking (BB) filters, which they claim will reduce the symptoms of digital eyestrain (DES). However, there is limited evidence to support the proposal that DES results from the blue light emitted by these devices.The visual and ocular symptoms commonly experienced when viewing digital screens are collectively termed DES. The emission spectrum of modern digital displays frequently includes a high percentage of blue light. Being higher in energy, these short wavelengths may contribute to DES. This study examined the effect of a BB filter on symptoms of DES during a sustained near-vision task.Twenty-three young, visually normal subjects were required to perform a 30-minute reading task from a tablet computer. The digital screen was overlaid with either a BB or neutral-density (ND) filter producing equal screen luminance. During each session, the accommodative response, pupil diameter, and vertical palpebral aperture dimension were measured at 0, 9, 19, and 29 minutes after the start of the reading task. Immediately following each session, subjects completed a questionnaire to quantify symptoms of DES.The BB filter blocked 99% of the wavelengths between 400 and 500 nm. The mean total symptom scores (±1 SEM) for the BB and ND filter conditions were 42.83 (3.58) and 42.61 (3.17), respectively (P = .62). No significant differences in accommodation or vertical palpebral aperture dimension were observed between the two filter conditions, although the magnitude of the mean accommodative response did increase significantly during the first 9 minutes of the task (P = .02).A filter that eliminated 99% of the emitted blue light was no more effective at reducing symptoms of DES than an equiluminant ND filter. There is little evidence at this time to support the use of BB filters to minimize near work-induced asthenopia.

OBJECTIVES To compare the effect of toric versus spherical soft contact lenses on objective measures of visual performance using visual acuity and electromyography of the orbicularis oculi muscle. METHODS Current soft contact lens wearers with -0.75 to -1.75 D astigmatism in each eye were binocularly fitted with toric (1-Day ACUVUE MOIST for astigmatism) and spherical (1-Day ACUVUE MOIST) contact lenses in random order. After each fitting and at 1-week follow-up, high- and low-contrast visual acuities were measured. Electromyography was used to objectively evaluate eyestrain. Linear mixed models were used to assess differences between toric and spherical contact lenses. RESULTS The mean age (±SD) of the 60 participants was 27.5±5.0 years, spherical refractive error was -3.68±2.01 D, and cylinder was -1.28±0.36 D. High- and low-contrast visual acuities with toric lenses were better than with spherical lenses at both fitting (toric high-contrast: -0.065±0.078 and low-contrast: 0.133±0.103 vs. spherical high-contrast: 0.001±0.104 and low-contrast: 0.224±0.107) and follow-up (toric high-contrast: -0.083±0.087 and low-contrast: 0.108±0.107 vs. spherical high-contrast: -0.015±0.095 and low-contrast: 0.211±0.104) (all P

Digital eye strain, an emerging public health issue, is a condition characterised by visual disturbance and/or ocular discomfort related to the use of digital devices and resulting from a range of stresses on the ocular environment. This review aims to provide an overview of the extensive literature on digital eye strain research with particular reference to the clinical management of symptoms. As many as 90 per cent of digital device users experience symptoms of digital eye strain. Many studies suggest that the following factors are associated with digital eye strain: uncorrected refractive error (including presbyopia), accommodative and vergence anomalies, altered blinking pattern (reduced rate and incomplete blinking), excessive exposure to intense light, closer working distance, and smaller font size. Since a symptom may be caused by one or more factors, a holistic approach should be adopted. The following management strategies have been suggested: (i) appropriate correction of refractive error, including astigmatism and presbyopia; (ii) management of vergence anomalies, with the aim of inducing or leaving a small amount of heterophoria (~1.5Δ Exo); (iii) blinking exercise/training to maintain normal blinking pattern; (iv) use of lubricating eye drops (artificial tears) to help alleviate dry eye-related symptoms; (v) contact lenses with enhanced comfort, particularly at end-of-day and in challenging environments; (vi) prescription of colour filters in all vision correction options, especially blue light-absorbing filters; and (vii) management of accommodative anomalies. Prevention is the main strategy for management of digital eye strain, which involves: (i) ensuring an ergonomic work environment and practice (through patient education and the implementation of ergonomic workplace policies); and (ii) visual examination and eye care to treat visual disorders. Special consideration is needed for people at a high risk of digital eye strain, such as computer workers and contact lens wearers.

Digital eye strain is a complex, multifactorial condition that can be caused by excessive screen time exposure to various electronic devices such as smartphones, tablets, e-readers, and computers. Current literature suggests oxidative damage concomitant with a chronic pro-inflammatory state represent significant etiopathogenic mechanisms. The present review aims to discuss the potential dietary role for micronutrients with nutraceutical properties to ameliorate various ocular and vision-related symptoms associated with digital eye strain. For ocular surface dysfunction, enhanced anti-inflammatory benefits with omega-3 polyunsaturated fatty acids have been well documented for treatment of dry eye disease. The anti-oxidative and immunosuppressive properties of anthocyanin phytochemicals may also confer protective effects against visually induced cognitive stress and digital asthenopia. Meanwhile, nutraceutical strategies involving xanthophyll macular carotenoids demonstrate enhanced cognitive functioning and overall visual performance that aids digital eye strain. Collectively, preliminary findings seem to offer a strong line of evidence to substantiate the need for additional randomized controlled trials aimed at treating digital eye strain with adjunctive nutraceutical strategies. Further RCT and comparisons on commercially available nutritional supplements are needed to quantify the clinical benefits.

Computer vision syndrome (CVS) is a very common phenomenon amongst computer users. A total of 90% of computer users, who spend more than 3 hours a day in front of the computer screen, suffer from CVS. CVS is also known as digital eye strain or visual fatigue and includes symptoms that are a result of continuous work in front of the different types of computer screens or other types of digital screens. An updated differentiation divides the cause of the symptoms into three separate categories which include visual symptoms, symptoms resulting from the digital screen itself and symptoms resulting from the ocular surface. CVS includes a wide range of symptoms which are non-specific (asthenopia), which include eye fatigue, eye strain, pain in and around the eye, blurred vision, headaches and even diplopia (double vision). Asthenopia and dry eye are the core symptoms of CVS. There are many solutions and ways to treat the different symptoms related to the vision, the screen and ocular surface and especially the symptoms related to the issue of dry eye. The treatment of CVS is focused around the different groups of symptoms and it is recommended to give a combined treatment for all the symptomatic groups. The correction of residual astigmatism, accommodation issues, base-in or base-up prisms and the correction of vergence reserves to maintain vision aspects. Changing the lighting, correct positioning of the screen and correcting the direction of gaze in relation to symptoms which are connected to the screen and artificial tears, as well as increasing the blink rate and increasing the level of moisture of the air in the room, all assist in treating the symptoms of dry eye. Blue light also has some effect on CVS and as a precaution it is recommended to reduce, as much as possible, blue light radiation that enters the eye or is emitted from the computer screen.

Prolonged viewing of 3D content may result in severe fatigue symptoms, giving negative user experience thus hindering the development of 3D industry. For 3D visual fatigue evaluation, previous studies focused on exploring the changes of frequency-domain features in EEG for various fatigue degrees. However, their time-domain features were scarcely investigated. In this study, a modified paradigm with a random disparities order is adopted to evoke the depth-related visual evoked potentials (DVEPs). Then the characteristics of the DVEPs components for various fatigue degrees are compared using one-way repeated-measurement ANOVA. Point-by-point permutation statistics revealed sample points from 100ms to 170ms - including P1 and N1 - in sensors Pz and P4 changed significantly with visual fatigue. More specifically, we find that the amplitudes of P1 and N1 change significantly when visual fatigue increases. Additionally, independent component analysis identify P1 and N1 which originate from posterior cingulate cortex are associated statistically with 3D visual fatigue. Our results indicate there is a significant correlation between 3D visual fatigue and P1 amplitude, as well as N1, of DVEPs on right parietal areas. We believe the characteristics (e.g., amplitude and latency) of identified components may be the indicators of 3D visual fatigue evaluation. Furthermore, we argue that 3D visual fatigue may be associated with the activities decrease of the attention and the processing capacity of disparity.

Objectives. This study aimed to describe the prevalence of ergonomic factors associated with computer vision syndrome (CVS), and knowledge and practices of computer usage among bank workers in the Cape Coast Metropolis, Ghana. Methods. A comprehensive eye examination was performed for 139 bankers in the Cape Coast Metropolis. Measurements of ergonomic practices at workstations were carried out and self-administered questionnaires were used to collect socio-demographic data, symptoms of CVS and associated factors as well as knowledge, attitudes and practices of the bankers on CVS. Descriptive statistics and logistic regression were carried out to compute the different proportions and relevant associations. Results. Headaches (73.4%), eyestrain (65.5%) and itching (63.3%) were the most common reported symptoms. The prevalence of CVS in the study population was 71.2% with a high level of poor ergonomic practices (78.4%) at computer workstations. With regard to knowledge, attitudes and practices of the participants on CVS, 68.3% of the participants had low levels of knowledge on CVS, while 90.6% had negative attitudes towards CVS and 46.0% of the participants had poor practices. Conclusion. Bankers had a high prevalence of CVS. Ergonomic practices, females and computer usage were all associated significantly with the presence of CVS.

Clinical relevance: Home-isolation and social distancing during the COVID-19 pandemic caused increased use of digital devices, posing a greater risk of developing digital eye strain-related symptoms. Eye-care professionals should educate patients about limiting screen time and managing digital eye strain symptoms. Background: This study aimed to evaluate the COVID-19 isolation’s impact on digital device use by comparing hours spent on digital devices before and during the 24-hour curfew in Saudi Arabia, while assessing the symptoms associated with digital eye strain. Methods: A self-reported questionnaire was used to compare the total hours per day, either continuous or intermittent, spent on digital devices during and before curfew, and the association of these durations with digital eye strain. Results: A total of 1,939 participants, (mean ± SD: 33 ± 12.2 years and 72% women) were recruited. Results showed a significant difference between usage duration before and during curfew. Digital eye strain incidence was 78% during the curfew. Chi-squared analysis indicated most symptoms are associated with usage duration and employment status. Multivariate analysis revealed significant associations between digital eye strain and the following factors: using more than one device (odds ratio 1.208, 95% confidence interval: 1.068-1.3661), age, optical correction, employment status, gender, using rewetting drops, and usage duration. Conclusions: In this population, prolonged use of digital devices significantly increased during home-isolation. Digital eye strain incidence increased during curfew. Regular eye exams should be encouraged to ensure the use of optimum prescription use and meet the specific visual demands required for the use of digital devices. Eye-health strategies and awareness campaigns should be employed on the importance of regular eye exams, decreasing screen time, practising the 20-20-20 rule, and the use of rewetting drops to help reduce the symptoms of digital eye strain during this period.

Near work has been considered to be a potential risk factor for the onset of myopia, but with inadequate evidence. Chinese adolescents use digital devices for near work, such as study and entertainment purposes, especially during the COVID-19 pandemic. In this study, we investigated the influence of prolonged periods of near work on accommodative response, accommodative microfluctuations (AMFs), and pupil diameter between juvenile subjects of myopia and emmetropia. Sixty juveniles (30 myopes and 30 emmetropes) were recruited for the study. Participants were instructed to play a video game on a tablet PC at a distance of 33.3 cm for 40 min. Accommodative response and pupil diameter were measured with an open-field infrared refractometer in High-speed mode. Parameters of the subjects were measured once every 10 min, and analyzed by one-way repeated measure ANOVA for variation tendency. There were no significant differences between emmetropia and myopia groups with respect to age and sex (p > 0.05). The low-frequency component (LFC) of myopia gradually increased with time, reached a peak at 30 min, and then declined (p = 0.043). The high-frequency component (HFC) of myopia also reached a peak at 30 min (p = 0.036). Nevertheless, there was no significant difference in the LFC (p = 0.171) or HFC (p = 0.278) of the emmetropia group at each time point. There was no significant difference in the mean and standard deviation of the accommodative response and pupil diameter both in emmetropic and myopic juveniles. Compared with juvenile emmetropes, myopes exhibit an unstable tendency in their accommodation system for prolonged near work at a certain time point. Accommodative microfluctuations may be a sensitive, objective indicator of fatigue under sustained near work in juvenile myopes.

Nowadays, more people tend to go to bed late and spend their sleep time with various electronic devices. At the same time, the BCI (brain–computer interface) rehabilitation equipment uses a visual display, thus it is necessary to evaluate the problem of visual fatigue to avoid the impact on the training effect. Therefore, it is very important to understand the impact of using electronic devices in a dark environment at night on human visual fatigue. This paper uses Matlab to write different color paradigm stimulations, uses a 4K display with an adjustable screen brightness to jointly design the experiment, uses eye tracker and g.tec Electroencephalogram (EEG) equipment to collect the signal, and then carries out data processing and analysis, finally obtaining the influence of the combination of different colors and different screen brightness on human visual fatigue in a dark environment. In this study, subjects were asked to evaluate their subjective (Likert scale) perception, and objective signals (pupil diameter, θ + α frequency band data) were collected in a dark environment (

Digital display use has been accepted as a contributing factor to dry eye disease. Nowadays, plenty of new models of digital displays have been developed, and the differences in their nature and the ways in which they are set and used may contribute to differences in the eye-related problems they cause.This study aimed to analyze the differences in ocular surface, tear film, and visual fatigue parameters after reading on different digital displays, with and without initial instillation of artificial tears.Thirty-one healthy individuals ranging in age from 20 to 26 years (mean ± standard deviation, 21.26 ± 1.73 years) were included in this prospective clinical study. Subjects' ocular surface, tear film, and visual fatigue parameters were assessed after reading for 15 minutes on a laptop computer, tablet, e-reader, and smartphone with matching characteristics and a baseline measurement. Measurements were taken with and without the instillation of artificial tears before the reading tasks and included the Ocular Surface Disease Index questionnaire, the Computer Vision Syndrome Questionnaire, tear meniscus height, the Schirmer I test, noninvasive keratograph break-up time, osmolarity, bulbar redness, and pupil size.Statistically significant differences in the Ocular Surface Disease Index, Computer Vision the Syndrome Questionnaire, tear meniscus height, the Schirmer I test, noninvasive keratograph break-up time, osmolarity, and bulbar redness were obtained when comparing the displays (P.05). Best results were obtained with the smartphone and the e-reader. Conversely, the computer produced the highest disturbance on the ocular surface and tear film. Finally, the instillation of artificial tears revealed no statistical improvement of ocular surface or tear film parameters for the same device (P.05).Taking into account the clinical tests for dry eye diagnosis, the smartphone may be considered as the least disturbing display, producing lower dry eye signs and symptoms in comparison with other devices.

Prolonged and continuous daily use of digital screens, or visual display terminals (VDTs), has become the norm in occupational, educational, and recreational settings. An increased global dependence on VDTs has led to a rise in associated visual complaints, including eye strain, ocular dryness, burning, blurred vision, and irritation, to name a few. The principal causes for VDT-associated visual discomfort are abnormalities with oculomotor/vergence systems and dry eye (DE). This review focuses on the latter, as advances in research have identified symptomology and ocular surface parameters that are shared between prolonged VDT users and DE, particularly the evaporative subtype. Several mechanisms have been implicated in VDT-associated DE, including blink anomalies, damaging light emission from modern devices, and inflammatory changes. The presence of preexisting DE has also been explored as an inciting and exacerbating factor. We review the associations between digital screens and DE, mechanisms of damage, and therapeutic options, hoping to raise awareness of this entity with the goal of reducing the global morbidity and economic impact of screen-associated visual disability.