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Objective: This cross-sectional study was done to find the prevalence of eye strain and other ocular morbidities among students in Udupi, Karnataka., Methods: The study protocol included interview, visual acuity examination using Snellen chart, and measuring classroom illumination through lux meter., Results: 26% students had visual morbidity and the most prevalent symptoms of eyestrain were headache (38.6%), watering of eyes (25.7%), pain around eyes (15.6%) and blurred vision (11.9%). 55.5% classrooms and 88.4% blackboards did not have proper illumination., Conclusion: Low classroom illumination levels may be a possible factor for development of visual morbidity.

Objective: To estimate the prevalence of asthenopia in 0-18 year-old children through a systematic review and meta-analysis of prevalence studies., Sources: Inclusion criteria were population-based studies from 1960 to May of 2014 reporting the prevalence of asthenopia in children. The search was performed independently by two reviewers in the PubMed, EMBASE, and LILACS databases, with no language restriction. This systematic review was performed in accordance with the Cochrane Collaboration guidelines and the PRISMA Statement. Downs and Black score was used for quality assessment., Summary of Findings: Out of 1692 potentially relevant citations retrieved from electronic databases and searches of reference lists, 26 were identified as potentially eligible. Five of these studies met the inclusion criteria, comprising a total of 2465 subjects. Pooled prevalence of asthenopia was 19.7% (12.4-26.4%). The majority of children with asthenopia did not present visual acuity or refraction abnormalities. The largest study evaluated 1448 children aged 6 years and estimated a prevalence of 12.6%. Associated risk factors were not clearly established., Conclusion: Although asthenopia is a frequent and relevant clinical problem in childhood, with potential consequences for learning, the scarcity of studies about the prevalence and clinical impact of asthenopia hinders the effective planning of public health measures., (Copyright © 2015 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.)

Objectives: To design and validate a questionnaire to measure visual symptoms related to exposure to computers in the workplace., Study Design and Setting: Our computer vision syndrome questionnaire (CVS-Q) was based on a literature review and validated through discussion with experts and performance of a pretest, pilot test, and retest. Content validity was evaluated by occupational health, optometry, and ophthalmology experts. Rasch analysis was used in the psychometric evaluation of the questionnaire. Criterion validity was determined by calculating the sensitivity and specificity, receiver operator characteristic curve, and cutoff point. Test-retest repeatability was tested using the intraclass correlation coefficient (ICC) and concordance by Cohen's kappa (κ)., Results: The CVS-Q was developed with wide consensus among experts and was well accepted by the target group. It assesses the frequency and intensity of 16 symptoms using a single rating scale (symptom severity) that fits the Rasch rating scale model well. The questionnaire has sensitivity and specificity over 70% and achieved good test-retest repeatability both for the scores obtained [ICC = 0.802; 95% confidence interval (CI): 0.673, 0.884] and CVS classification (κ = 0.612; 95% CI: 0.384, 0.839)., Conclusion: The CVS-Q has acceptable psychometric properties, making it a valid and reliable tool to control the visual health of computer workers, and can potentially be used in clinical trials and outcome research., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: The high number of computer workers wearing contact lenses raises the question whether the sum of these two risk factors for eye health may cause a worsening of Computer Vision Syndrome. The aim of this review is to synthesize the knowledge about ocular and visual alterations related with computer use in contact lens wearers., Methods: International review of scientific papers (2003-2013) in Spanish and English, using Scoping Review method, in Medline through PubMed and in Scopus., Results: The initial search provided 114 references, after applying inclusion/exclusion criteria six of them were included. All of them reveal that symptoms when using computer are more prevalent in contact lens wearers, with values of symptoms presentation prevalence ranging from 95.0% to 16.9% in wearers and from 57.5% to 9.9% in non-wearers, and four times more likely to develop dry eye [OR: 4.07 (95% CI: 3.52 to 4.71)]., Conclusion: Computer workers suffer more ocular and visual disturbances if they also are contact lens users, but studies are few and non conclusive. Likewise, further research regarding contact lens type and their conditions of use, both in symptoms and tear quality and ocular surface are needed. Silicone hydrogel lenses are associated with more comfort.

Background: Symptoms from the eyes are common among computer users. Knowledge is scarce about these problems, however., Objectives: The aim was to study risk-factors, incidence and persistence of eye-symptoms among professionally active computer users., Methods: This was a questionnaire based prospective study where 1283 males and females from different professions and companies answered a baseline questionnaire about individual factors and working conditions, e.g. duration of daily computer work, comfort of screen work, psychosocial factors. Subjects were at baseline and 10 follow-ups asked about the number of days with eye-symptoms during the preceding month., Results: The incidence-rate of symptoms persisting minimum three days was 0.38/person-year. A multivariate Hazard-ratio model showed significant associations with extended continuous computer work, tasks with high demands on eye-hand coordination, low level of control, visual discomfort, female sex and nicotine use. Eye-symptoms at baseline was a strong risk factor for new symptoms., Conclusion: The incidence of eye-symptoms among professional computer users is high and related to both individual and work-related factors. The organization of computer work should secure frequent breaks from near-work at the computer screen. The severity of vision-related problems could in field studies be quantified by asking for the persistence of symptoms.

Introduction: Computer vision syndrome (CVS) is a condition in which a person experiences one or more of eye symptoms as a result of prolonged working on a computer., Objectives: To determine the prevalence of CVS symptoms, knowledge and practices of computer use in students studying in different universities in Malaysia, and to evaluate the association of various factors in computer use with the occurrence of symptoms., Material and Methods: In a cross sectional, questionnaire survey study, data was collected in college students regarding the demography, use of spectacles, duration of daily continuous use of computer, symptoms of CVS, preventive measures taken to reduce the symptoms, use of radiation filter on the computer screen, and lighting in the room., Results: A total of 795 students, aged between 18 and 25 years, from five universities in Malaysia were surveyed. The prevalence of symptoms of CVS (one or more) was found to be 89.9%; the most disturbing symptom was headache (19.7%) followed by eye strain (16.4%). Students who used computer for more than 2 hours per day experienced significantly more symptoms of CVS (p=0.0001). Looking at far objects in-between the work was significantly (p=0.0008) associated with less frequency of CVS symptoms. The use of radiation filter on the screen (p=0.6777) did not help in reducing the CVS symptoms., Conclusion: Ninety percent of university students in Malaysia experienced symptoms related to CVS, which was seen more often in those who used computer for more than 2 hours continuously per day., (© NEPjOPH.)

Children of footwear making units are working in the soling process. The process includes fixing of upper part with the sole of the footwear. The adhesives contain a mix of organic solvents, which are released in the working environment and cause irritation and lacrimation of eyes. In addition poor illumination and ventilation further aggravates the eyestrain. The present study was carried out to find out the prevalence and the associated factors of eyestrain in working children of footwear making units. The study included 139 exposed and 160 comparison group subjects. Self-reported eyestrain was recorded through personal interview. The prevalence of eyestrain in child laborers was 25.9%, which was significantly more than the 12.4% prevalence in comparison group subjects (P=0.01). Working children of footwear making units were at 2.4 times higher risk of developing eyestrain as compared to comparison group subjects, though statistically non significant. Significantly higher proportion of eyestrain was reported in those aged >12 years, males and those working daily for >4 hours. The higher prevalence of eyestrain in the working children of footwear units may be attributed to exposure to workplace factors.

Background: The increasing popularity of commercial movies showing three dimensional (3D) computer generated images has raised concern about image safety and possible side effects on population health.This study aims to (1) quantify the occurrence of visually induced symptoms suffered by the spectators during and after viewing a commercial 3D movie and (2) to assess individual and environmental factors associated to those symptoms., Methods: A cross-sectional survey was carried out using a paper based, self administered questionnaire. The questionnaire includes individual and movie characteristics and selected visually induced symptoms (tired eyes, double vision, headache, dizziness, nausea and palpitations). Symptoms were queried at 3 different times: during, right after and after 2 hours from the movie., Results: We collected 953 questionnaires. In our sample, 539 (60.4%) individuals reported 1 or more symptoms during the movie, 392 (43.2%) right after and 139 (15.3%) at 2 hours from the movie. The most frequently reported symptoms were tired eyes (during the movie by 34.8%, right after by 24.0%, after 2 hours by 5.7% of individuals) and headache (during the movie by 13.7%, right after by 16.8%, after 2 hours by 8.3% of individuals). Individual history for frequent headache was associated with tired eyes (OR = 1.34, 95%CI = 1.01-1.79), double vision (OR = 1.96; 95%CI = 1.13-3.41), headache (OR = 2.09; 95%CI = 1.41-3.10) during the movie and of headache after the movie (OR = 1.64; 95%CI = 1.16-2.32). Individual susceptibility to car sickness, dizziness, anxiety level, movie show time, animation 3D movie were also associated to several other symptoms., Conclusions: The high occurrence of visually induced symptoms resulting from this survey suggests the need of raising public awareness on possible discomfort that susceptible individuals may suffer during and after the vision of 3D movies.

The aims of this study were to investigate work conditions, to estimate the prevalence and to describe risk factors associated with Computer Vision Syndrome among two call centers' operators in São Paulo (n = 476). The methods include a quantitative cross-sectional observational study and an ergonomic work analysis, using work observation, interviews and questionnaires. The case definition was the presence of one or more specific ocular symptoms answered as always, often or sometimes. The multiple logistic regression model, were created using the stepwise forward likelihood method and remained the variables with levels below 5% (p < 0.05). The operators were mainly female and young (from 15 to 24 years old). The call center was opened 24 hours and the operators weekly hours were 36 hours with break time from 21 to 35 minutes per day. The symptoms reported were eye fatigue (73.9%), "weight" in the eyes (68.2%), "burning" eyes (54.6%), tearing (43.9%) and weakening of vision (43.5%). The prevalence of Computer Vision Syndrome was 54.6%. Associations verified were: being female (OR 2.6, 95% CI 1.6 to 4.1), lack of recognition at work (OR 1.4, 95% CI 1.1 to 1.8), organization of work in call center (OR 1.4, 95% CI 1.1 to 1.7) and high demand at work (OR 1.1, 95% CI 1.0 to 1.3). The organization and psychosocial factors at work should be included in prevention programs of visual syndrome among call centers' operators.

Objective: To analyze and explore the epidemiological characteristicss and related factors for visual fatigue among university students in Haidian District of Beijing., Methods: The investigation with questionnaires was conducted in 2 246 undergraduates and postgraduates from four universities in Haidian District by multi-level stratified cluster sampling. Factor analysis and multivariate Logistic regression model were conducted to explore the related factors for visual fatigue., Results: Among the university students, the total prevalence rate of visual fatigue was 64.9%, and the prevalence rates of males, females, undergraduates and postgraduates were 65.1%, 64.7%, 58.9% and 75.7%, respectively. The result of multivariate logistic regression analysis showed that bad living environment conditions, improper computer use and bad health status were significantly associated with increased risk of visual fatigue, the ORs (95% CI) were 1.185 (1.078, 1.302), 1.490 (1.355, 1.640) and 1.323 (1.182, 1.481), respectively; good sleep and mental status, good psycho-social state, and good factors of habits and diets might be protective against visual fatigue, the ORs (95% CI) were 0.691 (0.628, 0.760), 0.793 (0.720, 0.873) and 0.649 (0.587, 0.717), respectively., Conclusion: The university students showed higher prevalence rate of visual fatigue. Psychological state, environment, health status, diets and habits were related to the development of visual fatigue. Health education should be strengthened among university students to prevent the adverse effects of visual fatigue on their health.

Working children of gem-polishing units are exposed to poor illumination and improper workstations. Also processes require lot of visual and mental concentration for precision. This may result in eyestrain. The study included 432 exposed and 569 comparison group subjects. Self-reported eyestrain was recorded through personal interview. Eyestrain included symptoms like itching, burning, or irritated eyes; tired or heavy eyes; difficulty seeing clearly (including blurred or double vision); and headache. The study variables included age, gender, daily working hours, and duration of exposure. The prevalence of eyestrain in child labourers was 32.2%, which was significantly more than the comparison group subjects. Also, the working children of gem-polishing units were at 1.4 times higher risk of developing eyestrain. Age (3)14 years and female gender were significantly associated with the eyestrain. The prevalence of eyestrain in child labourers was 32.2% and was associated with age (3)14 years and female gender.

Background: The aim of the study was to measure the prevalence and intensity of eye symptoms in office workers who use computers on a regular basis, and to find out if the symptoms depend on the duration of computer use and other work-related factors., Material and Methods: Office workers employed at large social services companies in two cities (Warszawa and Katowice) were invited to fill in a questionnaire (cross-sectional study). The questions included work history and history of last-week eye symptoms and eye-related complains. Altogether 477 men and women returned the completed questionnaires. Between-group symptom differences were tested by the chi-square test and verified by the results of multivariate logistic analysis. The examined effects included the role of daily computer use and lighting conditions at work stations., Results: The examined persons complained of such eye symptoms as eye strain, visual acuity impairment and mucosal dryness or eye burning. The following values of symptom prevalence were found in women and men, respectively: eye strain 50.7% and 32.6%, disturbed visual acuity 38.3% and 21.2%, mucosal dryness and eye burning 46.5% and 24.2%. The results of multivariate analysis confirmed the statistically significant effects of lighting intensity and screen flickering on the occurrence of symptoms., Conclusions: Frequent occurrence of eye symptoms and their associatation with some characteristics of the work environment point to the need of observing ergonomic standards of work stations and of the usage of computers at work.

Background: The aim of this study was to assess the impact of the visual work on the tear film and the degree of eye strain., Materials and Methods: The survey was conducted among 50 people working 4 h with different types of monitors (CRT, LCD) and without a monitor. Schirmer's test and evaluation of the degree of eye strain were performed in all subjects before and after work., Results: The studies revealed no significant change in Schirmer's test. Most people reported eye fatigue after every kind of visual work. The highest degree of eye strain was noted after work with the CRT display screen, especially among people with dry eye syndrome., Conclusion: The studies revealed no significant impact of various visual works on the tear film. However, they showed that any kind of intense eye work may cause eye irritation and strain, particularly in the people affected by dry eye syndrome.

This study investigated how perceived job stress and health status differ, as well as the relationships to inbound (incoming calls) versus outbound (outgoing calls) calling activities, for call center workers in a bank in Taiwan. The sample bank employed 289 call center workers at the time of the survey, ranging in age from 19 to 54 yr old. Data were obtained on individual factors, health complaints, perceived level job stress, and major job stressors. Overall, 33.5% of outbound operators and 27.1% of inbound operators reported frequently or always experiencing high stress at work, however, the differences between inbound and outbound operators were insignificant. "Having to deal with difficult customers" was the most frequent job stressor for all workers. Musculoskeletal discomfort, eye strain, and hoarse or sore throat were the most prevalent complaints among call center workers. The relationship between perceived job stress and health complaints indicated that workers who perceived higher job stress had significantly increased risk of multiple health problems, including eye strain, tinnitus, hoarse or sore throat, chronic cough with phlegm, chest tightness, irritable stomach or peptic ulcers, and musculoskeletal discomfort (with odds ratios ranging from 2.13 to 8.24). These analytical results suggest that perceived job stress in the call center profoundly affected worker health. This study identified main types of job stressors requiring further investigation.

Objective: To determine the effects of obstructive sleep apnea (OSA) on visual vigilance during simulated automobile driving., Methods: Twenty-five drivers with OSA and 41 comparison drivers participated in an hour-long drive in a high-fidelity driving simulator. Drivers responded to light targets flashed at seven locations across the forward horizon. Dependent measures were percent correct [hit rate (HR)] and reaction time (RT). Self-assessment of sleepiness used the Stanford Sleepiness Scale (SSS) before and after the drive and the Epworth Sleepiness Scale (ESS)., Results: OSA drivers showed reduced vigilance based on lower HR than comparison drivers, especially for peripheral targets (80.7+/-14.8% vs. 86.7+/-8.8%, P=.03). OSA drivers were sleepier at the end of the drive than comparison drivers (SSS=4.2+/-1.2 vs. 3.6+/-1.2, P=.03), and increased sleepiness correlated with decreased HR only in those with OSA (r=-0.49, P=.01). Lower HR and higher post-drive SSS predicted greater numbers of driving errors in all subjects. Yet, ESS, predrive SSS, and most objective measures of disease severity failed to predict driving and vigilance performance in OSA., Conclusions: Reduced vigilance for peripheral visual targets indicates that OSA drivers have restriction of their effective field of view, which may partly explain their increased crash risk. This fatigue-related decline in attention is predicted by increased subjective sleepiness during driving. These findings may suggest a means of identifying and counseling high-risk drivers and aid in the development of in-vehicle alerting and warning devices.

Purpose: To determine the prevalence of refractive errors and binocular disorders in relation to asthenopia in a representative population of Swedish schoolchildren., Methods: The study population included 216 schoolchildren, 60 in grade 1 (age 6-7 years), 96 in grade 4 (10-12 years) and 60 in grade 8 (14-16 years). Asthenopia was evaluated by questionnaire. Visual acuity was tested for distance and near, uncorrected and with the best subjective refraction. Refraction in cycloplegia and an orthoptic assessment was performed., Results: Asthenopia was reported in 23.1% of schoolchildren; all but two of these schoolchildren had an abnormal eye examination. Asthenopia was related to uncorrected visual acuity < or = 0.65 (13.9%*) and myopia (8.8%*). No significant correlation could be found to accommodative or convergence insufficiency., Conclusion: Asthenopia was significantly associated with uncorrected visual acuity < or = 0.65 and with myopia (spherical equivalent -0.50 D or less) among Swedish schoolchildren.

Context: There is growing body of evidence that use of computers can adversely affect the visual health. Considering the rising number of computer users in India, computer-related asthenopia might take an epidemic form. In view of that, this study was undertaken to find out the magnitude of asthenopia in computer operators and its relationship with various personal and workplace factors., Aims: To study the prevalence of asthenopia among computer operators and its association with various epidemiological factors., Settings and Design: Community-based cross-sectional study of 419 subjects who work on computer for varying period of time., Materials and Methods: Four hundred forty computer operators working in different institutes were selected randomly. Twenty-one did not participate in the study, making the nonresponse rate 4.8%. Rest of the subjects (n = 419) were asked to fill a pre-tested questionnaire, after obtaining their verbal consent. Other relevant information was obtained by personal interview and inspection of workstation., Statistical Analysis Used: Simple proportions and Chi-square test., Results: Among the 419 subjects studied, 194 (46.3%) suffered from asthenopia during or after work on computer. Marginally higher proportion of asthenopia was noted in females compared to males. Occurrence of asthenopia was significantly associated with age of starting use of computer, presence of refractive error, viewing distance, level of top of the computer screen with respect to eyes, use of antiglare screen and adjustment of contrast and brightness of monitor screen., Conclusions: Prevalence of asthenopia was noted to be quite high among computer operators, particularly in those who started its use at an early age. Individual as well as work-related factors were found to be predictive of asthenopia.

This study investigated the effect of moving from single-occupancy offices to a landscape environment. Thirty-two visual display unit (VDU) operators reported no significant change in visual discomfort. Lighting conditions and glare reported subjectively showed no significant correlation with visual discomfort. Experience of pain was found to reduce subjectively rated work capacity during VDU tasks. The correlation between visual discomfort and reduced work capacity for single-occupancy offices was rs=.88 (p=.000) and for office landscape rs=.82 (p=.000). Eye blink rate during habitual VDU work was recorded for 12 operators randomly selected from the 32 participants in the office landscape. A marked drop in eye blink rate during VDU work was found compared to eye blink rate during easy conversation. There were no significant changes in pain intensity in the neck, shoulder, forearm, wrist/hand, back or headache (.24

The aim of this study was to investigate the relationship between asthenopia and work with video display terminals (VDT). 62 office workers (29 males and 33 females), that use VDT for more than 20 hours each week, were investigated by means of standardized questionnaires (elaborated by the Italian Society of Occupational Medicine and Industrial Hygiene). The authors analyzed the prevalence of occupational asthenopia and its correlation with the duration of weekly VDT use and the presence of refractive alterations. It was demonstrated a prevalence of asthenopia of 51% and a statistically significant correlation between the entity of asthenopic symptoms and number of weekly hours and years of work at VDT, in particular in subjects with presbyopia.

Purpose: To study the knowledge, attitude and practices (KAP) towards computer vision syndrome prevalent in Indian ophthalmologists and to assess whether 'computer use by practitioners' had any bearing on the knowledge and practices in computer vision syndrome (CVS)., Materials and Methods: A random KAP survey was carried out on 300 Indian ophthalmologists using a 34-point spot-questionnaire in January 2005., Results: All the doctors who responded were aware of CVS. The chief presenting symptoms were eyestrain (97.8%), headache (82.1%), tiredness and burning sensation (79.1%), watering (66.4%) and redness (61.2%). Ophthalmologists using computers reported that focusing from distance to near and vice versa (P =0.006, chi2 test), blurred vision at a distance (P =0.016, chi2 test) and blepharospasm (P =0.026, chi2 test) formed part of the syndrome. The main mode of treatment used was tear substitutes. Half of ophthalmologists (50.7%) were not prescribing any spectacles. They did not have any preference for any special type of glasses (68.7%) or spectral filters. Computer-users were more likely to prescribe sedatives/anxiolytics (P = 0.04, chi2 test), spectacles (P = 0.02, chi2 test) and conscious frequent blinking (P = 0.003, chi2 test) than the non-computer-users., Conclusions: All respondents were aware of CVS. Confusion regarding treatment guidelines was observed in both groups. Computer-using ophthalmologists were more informed of symptoms and diagnostic signs but were misinformed about treatment modalities.

The present study examined the relationship of work duration or physical symptoms to the mental health of visual display terminal (VDT) workers in Japan. The mental health status of 2,327 VDT users at an administrative office was investigated using the 12-item General Health Questionnaire (GHQ-12). Subjects were asked about their age, sex, hours of daily VDT use, rest and breaks during VDT work, eyestrain, and musculoskeletal pain. Logistic regression analysis was used to evaluate the associations with mental health status (GHQ-12 scores). The mean age of subjects was 39.5 yr (SD=10.3). Among all subjects, 36.7% could rest during VDT work and 66.9% received breaks during VDT work. The proportion of subjects who reported eyestrain and musculoskeletal pain were 19.6% and 25.7%, respectively. Eighteen percent of subjects were classified into a GHQ-12 high score group. Logistic regression analysis showed that age less than 40 yr, not receiving breaks during VDT work, and the presence of eyestrain and musculoskeletal pain were significantly associated with poor mental health status (high GHQ-12 scores). Using a VDT for more than 5 h/d and being female were also marginally associated with high GHQ scores (p<0.1). In conclusion, the management of physical health as well as work duration is important for good mental health status among VDT users.

VDT (Visual Display Terminals) are commonly used in a wide range of occupational fields. Over the last ten years a number of studies have shown that ocular symptoms are the form of discomfort most frequently experienced by subjects who work at VDT. The symptoms as a whole characterize a complex syndrome named "asthenopia" and have been seen as a consequence of prolonged, fixed and closely oriented vision. In our study we have evaluated data derived from a standardized questionnaire (a series of questions elaborated and promoted by the Italian Society of Occupational Medicine and Industrial Hygiene). It was administered to a group of 191 workers who utilise VDT for more than 20 hours each week. We also took into consideration the results of ophthalmologic medical examinations performed on this particular group of workers. Prevalence of occupational asthenopia we found to be lower in this group than in the case of other reported investigations, though it proved to be higher in the case of female subjects. According to the Literature, symptoms intensity is related to the duration of weekly VDT use, there being no significant association with the number of years spent working at VDT. Our results show that prevalence of asthenopia was not significantly influenced by refractive alterations and this unexpected outcome might be explained by taking into account the small-size group of subjects affected by hypermetropic defects. It is well known that these are the most important factors in conditioning asthenopia. Our finding indicates the need for further research, which should include a larger group of VDT workers with refractive alterations and furthermore take into consideration environmental variables such as climate and illumination, since these are co-aetiological factors, known or suspected, of occupational asthenopia.

Background: This study was conducted for a UK Trade Union in response to increasing numbers of health complaints among intensive computer workers in a data processing environment., Aim: To estimate prevalence of musculoskeletal pain/discomfort and visual strain symptoms among data processing workers and to explore associations with work factors., Methods: A self-report questionnaire was distributed to data processors (n = 175) and a control group (n = 129) in the same organization., Results: Eighty-six per cent of data processors reported musculoskeletal pain/discomfort in the previous year, with the highest prevalence rate found for the neck (58%). The 12 month reported prevalence for visual strain symptoms was 47%, tired eyes (41%) was the most commonly reported symptom. In the last week, 56% reported pain/discomfort and 25% visual strain symptoms. Data processors reporting pain in the previous year were more likely to be dissatisfied with their jobs (P < 0.01), to report a lack of choice in deciding what they did at work (P < 0.02), to have insufficient time to complete work (P < 0.05) or to receive help from others when time was limited (P < 0.03)., Conclusion: The prevalence of self-reported musculoskeletal pain/discomfort and visual strain symptoms was high among data processors. A systematic approach to risk reduction addressing organizational, psychosocial and physical work factors is required. This study has implications for reorganization of this and other intensive computer work, given the increasing requirement for intensive computing work in many industrial sectors. More research is needed to investigate interactions between job demands and support systems for these workers.

Objective: To determine the prevalence of and factors contributing to eye strain among radiologists, we examined the influence of the viewing method (PACS vs hard-copy film), age, case volume, technique, work habits, and workstation design on symptoms., Materials and Methods: An Internet-based survey was sent to 2,700 radiologists randomly selected from the membership database of the Radiological Society of North America. Questions included demographic information, viewing method, work habits, and workstation design. Common eye strain symptoms were evaluated on a 5-point Likert scale. Chi-square analysis, analysis of variance, and step-wise and regression analyses were performed to evaluate codependence of the explanatory variables with eye strain., Results: The adjusted response rate was 14% (380 respondents). The largest age cohort was 36-50 years. The prevalence of eye strain was 36% and was not affected by the viewing method (PACS vs film). Increased symptoms could be independently predicted in radiologists who were women (p <0.001), had longer work days (p=0.009), took fewer breaks (p=0.03), reported screen flicker (p=0.0003), and performed CT screening (p=0.04). Working hours had the strongest influence on eye strain. Eye strain was increased in those who reported studies for longer than 6 hr per day (p=0.01) and decreased in those who took breaks every hour (p=0.04). Symptoms were independent of the length of the break taken and of other workstation and technique factors., Conclusion: Eye strain was common among the radiologists in our study population, with no significant difference between PACS and hard-copy film users. Taking frequent short breaks, eliminating screen flicker, and limiting the number of CT screening studies interpreted may improve symptoms.

With the spread of visual display terminals (VDT) in offices, the numbers of workers using VDT and the working hours at such equipment have increased rapidly in recent years. Also, preventive measures for fatigue have been proposed and the office-working environment has been improved. To examine the effects of the rapid changes in working conditions and environment on the health of VDT workers, we conducted a questionnaire survey in 2002. A self-reported questionnaire was distributed to 3,927 office workers; 2,374 (60.5%) responded. Subjects whose questionnaires had missing data were excluded from analysis. As a result, 1,406 (male: 1,069, female: 337) workers aged 20 to 59 were subjected to analysis. By a logistic regression model, we examined the association between VDT use and visual and musculoskeletal symptoms. Prevalence of eye strain and/or pain (72.1%) was the highest, followed by neck stiffness and/or pain (59.3%), low back stiffness and/or pain (30.0%) and hand or arm strain and/or pain (13.9%). Women consistently reported more discomfort than men. As a result of the logistic regression model, eye strain and/or pain was associated with dissatisfaction with airflow, but not with factors affecting visual symptoms as reported in previous studies, for example, reflection of light and blurred characters on the screen. It was thought that airflow appeared as a risk factor because the lighting environment had been improved in offices to prevent reflection of light on the screen. Neck stiffness and/or pain was associated with raising the shoulders during VDT work, the unsuitable shape of the computer mouse for a hand, and the inconvenient arrangement of the mouse in relation to the body. Hand or arm strain and/or pain were associated with the arrangement of the mouse and inappropriate height of the desk. Low back stiffness and/or pain were associated with dissatisfaction with the chair and using the keyboard without a wrist rest. Although measures to prevent fatigue had been implemented for VDT workers, risk factors for musculoskeletal symptoms would be the same as in previous studies.

Background: Since the use of video display units (VDU) has become widespread in the workplace, more and more research has been conducted to evaluate the possible onset of adverse effects., Objectives: We carried out a multidisciplinary investigation on a group of 660 VDU operators working for a service agency, aimed at analysing the relationship between ophthalmological, musculoskeletal and neuropsychological parameters and asthenopia., Methods: In this study we propose a method for a qualitative and quantitative evaluation of the asthenopic syndrome based on data collected with an easy semi-structured questionnaire., Results and Conclusions: No relationship between asthenopia and refractive alteration was noted, whereas a significant association was observed between a lengthened convergence near point and the average time of daily VDU exposure. A significant relationship was also shown between asthenopia, cervical and lumbar disorders, and neuropsychological symptoms. The method for evaluation of asthenopia and the results of this study suggest useful implications in health surveillance programs. After an appropriate validation procedure, this method could represent a useful screening tool and a valid support for preventive interventions. The use of this instrument in longitudinal studies will also provide the opportunity of verifying the existence of long-term effects due to VDU exposure.

Objective: To report the relative frequency of the asthenopic complaints in an african black population., Methods: Data from 184 records of African black subjects with asthenopic complaints and a normal ocular examination between January 1996 and December 1998 were considered., Results: There were 87 males (47.3%) and 97 females (52.7%). The mean age was 24.6 +/- 9.2 years with a sex ratio of 1:1. Asthenopic symptoms were: headache (47.0%), ocular pain (37.0%), tearing (24.5%), blurred vision (23.4%), photophobia (20.1%), burning sensation (12.5%), foreign-body sensation (8.7%), red eyes (4.3%) and diplopia (4.3%). Asthenopic subjects with headache had more associated symptoms. Headache was 2-3 times more frequently associated with the presence of tearing, foreign-body sensation and burning complaints than others., Conclusion: African black people seem to present the same asthenopic symptoms as in other races. Headache is the main symptom. Tearing, foreign-body and burning sensation are the most common complaints associated with asthenopic headache.

The article demonstrates analysis of present methods aimed at functional stimulation of vision. The authors show leading role of laser stimulation methods, justify terms--"operative" and "long-term" correction of vision--referring to occupational activities of aviation professionals.

A large number of workers are currently employed in tasks involving the use of computer based equipment. Much research has been carried out both on prevalence and incidence of ocular and visual disorders as well as on occupational asthenopia. Less attention has been given to investigating the possibility of a microbiological pollution of Video Display Unit (VDU) workstations and to the consequent possible development of work-related ocular infections. The authors investigated the presence of bacteria and fungi on Computer Assisted Design (CAD) workstations and in the conjunctival sac of the operators.

To investigate the relationship between asthenopia of VDT workers and the ocular alignment, we measured far and near alignment of 407 subjects (74 VDT workers with asthenopia, 137 VDT workers without asthenopia, and 196 non-VDT workers) using Total Vision tester (VT-500). There was no relationship between the asthenopia and the records of far alignment test. On the other hand, the incidence of exophoria and convergence insufficiency type in near alignment test was significantly high in the group of VDT workers with asthenopia. From these results, we speculate that cases who have exophoria or show incomplete fusional response measured under the near testing distance (50 cm) tend to complain of asthenopia.

Objective: To study the incidence of asthenopia among computer terminal operators as compared to unexposed administrative workers and to identify the risk factors associated with this condition., Material and Methods: A sample of 35 computer terminal operators and 70 unexposed administrative workers from eight computing centers at an educational institution were included in the study. The risk factors studied were: lighting, contrast, type of lighting, screen type, electrostatic field, eye to monitor distance, time and number of hours worked, age, use of corrective lenses, seniority and overtime. Asthenopia was clinically identified as the presence of at least one sign and symptom present in a given workday., Results: Asthenopia was found in 68.5% of the exposed group and in 47.7% of the unexposed group (p < 0.05). Among the risk factors studied, working for more than four hours at the video display terminal was shown to have a significant association with asthenopia (p < 0.05)., Conclusions: A recommendation is made to take breaks during the workday at computer terminals in order to avoid visual fatigue. Also, more extensive studies should be carried out in our population to establish safety criteria and to standardize work activities using computer terminals.

Background: The use of video display terminals (VDT) in the workplace is growing rapidly. Visual problems associated with computer use are increasing apace. Recognizing and addressing these needs are vital tasks for the optometric practitioner. This paper examines the demographics, prevalence of symptoms, and other work- and vision-related factors among VDT workers. Understanding the characteristics of a typical patient can aid in developing effective treatment protocols., Methods: Twenty-two optometrists collected data from 324 patients who work on VDT screens for a minimum of 2 hours per day. A questionnaire was used to collect the data. Along with reporting the patients' dry manifest refraction results, the survey instrument also included a self-report of experienced symptoms., Results: The prototypical patient, based on the total subject population, is a 38-year old, mildly myopic female who uses the computer screen about 5 hours per day. Average total VDT work experience is about 5 years. Most of the patients use full-color screens and sit between 21 and 22 inches away from the screen. A variety of visual symptoms is reported, with eyestrain (65 percent) and headaches (42 percent) being the most common complaints., Conclusions: Between 75 percent (results of this study) and 88 percent (reported by NIOSH) of patients who use a VDT regularly are likely to be symptomatic. This study has helped to identify the "typical" VDT user and the symptoms this user is most likely to report. The next step is to develop a diagnostic and treatment protocol by which optometrists can prescribe for and potentially prevent these computer-related vision problems.

Virtual reality (VR) has become increasingly well-known over the last few years. However, little is known about the side-effects of prolonged immersion in VR. This study set out to investigate the frequency of occurrence and severity of side-effects of using an immersion VR system. Out of 146 subjects, 61% reported symptoms of malaise at some point during a 20-min immersion and 10-min post-immersion period. These ranged from symptoms such as dizziness, stomach awareness, headaches, eyestrain and lightheadedness to severe nausea. These symptoms caused 5% of the subjects to withdraw from the experiment before completing their 20-min immersion period. Further research needs to be conducted that attempts to identify those factors that play a causative role in the side-effects of the VR system, and that looks for methods of reducing these side-effects.

In order to evaluate factors affecting visual and musculoskeletal symptoms by visual display terminal (VDT) operation, a questionnaire survey was conducted among clerical workers in Chiba university. The results were as follows: 1) Of these workers, 81.9% engaged in VDT operation. For most of the subjective symptoms, the prevalence rates tended to increase with the degree of VDT use. 2) These complaints were combined to give visual and musculoskeletal symptom scores. Both of the scores were higher among females than males, and the musculoskeletal symptom score was significantly higher. No difference was found in regard to age. 3) Analysis using log-linear models was performed to evaluate the effects of sex and age. The results showed that the visual and musculoskeletal symptom scores were significantly higher among the workers operating VDTs for one or more hours per day than among those who did not operate them at all. Analysis of the effects of VDT workloads revealed that VDT use for five or more days per week significantly increased the prevalence rates of both symptoms. Their use for less than four days per week affected neither of the symptoms. With regard to operating time per day or length of VDT use, no differences were found. 4) This investigation suggested that the VDT workloads were not so heavy and that the effects on each symptom were minor among the subjects of the present survey. However, it is important that consideration be given to ensure that the workloads for workers who operate VDTs every day not be too heavy.

The paper gives the findings of the long-term computer study of the influence of the lessons with computer on the functional state of schoolchildren of different ages. Regularities in the change of the working capacity and the functional state of children under the influence of computer lessons have been determined. It has been shown that the adaptation to computer activity takes place according to age. Schoolchildren aged 7 and 10-11 years have a lot of difficulties in adaptation. The degree of fatigue depends on the conditions of the lessons with computer, on the display type, duration, maintenance and regime of the lessons. The differential hygienic regulations of the optimum continuous duration of the lessons with computer during educational and extra educational time.

A group of military servicemen were deprived of sleep for 65 h while they carried out a simulated military mission with a high visual workload. Their performance in a series of near vision tests was monitored. In general, the visual system was found to be resilient to the stress of sleep loss, the subjects experiencing mild symptoms of asthenopia (eyestrain). However, after 48 h without sleep there was a reduction in amplitude of convergent fusional reserves and a decrease in contrast sensitivity to a spatial frequency of 6 cycles/degree. A disruption in diurnal rhythms for these parameters was suggested. The results are considered in terms of the maintenance of visual efficiency and comfort with loss of sleep, and have implications for both the military and civilians involved in shift work and long work schedules.

Fifty-seven Chinese female Video Display Unit operators employed in a multi-national company were asked to complete the 28-item General Health Questionnaire (GHQ-28). This is part of a study on stress and asthenopia in this group of workers. Validity of the GHQ-28 was determined by comparison with the Clinical Interview Schedule (CIS). The GHQ-28 was found to give optimum results with a cut-off score of 5/6. The CIS classified 28.07% as cases and this was comparable to the estimated prevalence of 28.03% derived from the GHQ.

In a study of VDT workers the relationship between 1) their general life condition and working environment and 2) their eye, shoulder, neck, arm, waist and back complaints and their psychological symptoms was investigated. The subjects of the study were (147 workers whose age ranged from 18 to 39 years, and who had used VDT for a monthly average of more than 40 h. The results were as follows: 1) For most of the symptoms, a tendency was observed for females to complain more than males and for younger workers to complain more than the older workers. Neck, shoulder, arm, waist and back complaints were more common than psychological symptoms. These physical complaints appeared to be the most common among VDT workers. 2) The occurrence of eye-related symptoms is related to items directly affecting sight. This reaffirms the importance of illumination for the visual system. 3) This investigation showed that a relatively good VDT working environment was secured for the subjects of the present study. It is important that consideration be given to labor management such as provision of rest period and supervision.

An epidemiological survey on 30,000VDT operators has been carried out to evaluate the relationship between asthenopia and monitor characteristics. A VDU operator has been classified as asthenopeic if he complained about at least two of the following ten symptoms: headache, tearing, eye smarting, blurred vision, double vision, ocular itching, photophobia, blinking, nausea, eye heaviness. Visual discomfort has been related to 1) the presence of flicker; the possibility to regulate, 2) brightness, 3) height; and 4) inclination of monitor. Asthenopia has resulted statistically correlated to the presence of flicker and to the impossibility of regulating height and inclination of monitor for both sexes. The possibility to regulate monitor brightness has not determined a reduction of visual discomfort either in men or in women.

The prevalence of general binocular dysfunction with asthenopia was determined for non-presbyopes at an urban optometry clinic serving municipal workers and their dependents. Of the sample of 119 patients, 42.9% had jobs with heavy desk work demands (primarily secretarial and clerical) and 39.5% were students. The prevalence of symptomatic general binocular dysfunction was 21.0%. Accommodative dysfunctions were the most commonly encountered condition at 16.8%. Symptomatic near esophoria was found in 5.9% of patients and convergence insufficiency in 4.2%. Both vergence dysfunctions overlapped with accommodative dysfunctions.

The lighting conditions, luminance, contrast, and design of the workplace were studied in video display terminal (VDT) work stations operated by a group of female VDT data-acquisition clerks. VDT-induced symptoms were assessed by means of subject answers to a questionnaire. To measure VDT-induced ocular fatigue objectively, refraction power was determined before and at the end of workshift by an infrared autorefractometer. Job-induced refraction changes were then related to visual complaints and conditions in the workplace. The results confirmed that VDT data-acquisition work can lead to temporary myopia (myopization) in a remarkable percentage of operators; a significant correlation between eye discomfort, ocular asthenopia, and myopization was also found. Illumination levels, luminance, and contrast seem to be of paramount importance regarding visual symptoms: neither asthenopia nor myopization was observed when all of these conditions were adequate. If the ergonomic design of the workplace and the viewing distance are adequate, there are also usually fewer musculoskeletal symptoms. Our results suggest that changes in the ocular refraction status before and at the end of the work-shift, as determined by an automatic refractometer, provide a good objective index of VDT-induced "ocular fatigue", which in our study proved to be significantly related to workplace conditions.

A large population of 2058 VDT operators from all compartments in Lombardia of a large national company was studied. An "ergophthalmological" questionnaire was administered to all subjects, followed by an ophthalmological-orthoptic examination. Ametropias showed a prevalence of 51.9%; the most common refractive defect was myopia followed by astigmatism and hyperopia. Heterophorias with bad or mediocre compensation had a prevalence of 4.1 and 11% respectively. The study of symptoms showed a frequency of 23.5% of intense asthenopic complaints and 21.1% of less severe and less frequent symptomatology. Asthenopia was significantly correlated (chi square) with sex, VDT exposure, refraction, presbyopia, and decompensated heterophorias.

In 1983, 285 (male: 129, female: 156) VDT workers and 60 (male: 30, female: 30) control subjects were examined in order to detect the factors affecting the subjective symptoms of VDT workers. Biological information (for example: sex, age), life histories, information about VDT work, tests (for example: visual acuity), symptoms and interferences to daily life of VDT workers and control subjects were collected. The following results were obtained. Female VDT workers experienced more fatigue from commuting to work, stiffness in shoulders, distant blurred vision complaints of visual acuity and sum of the scores of ocular complaints than female control subjects. Only among female VDT workers, the longer the daily working hours, the greater were their ocular symptoms. A remarkable relationships were observed between psychological burden factors (for example: self-control of VDT work, sensation of excessive VDT work) and subjective symptoms of the VDT workers (both sexes). In particular, VDT workers who considered VDT work to be excessive had marked by greater subjective symptoms than those who did not.