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We suggest a low-vision reading aid based on user-customized text presented on a head-mounted display (HMD), and make an initial comparison to optical aids in participants with age-related macular degeneration (AMD). Biomimetic scrolling, a novel method of text presentation which mimics the natural movements of the eye while reading, was previously invented: while the user maintains a steady gaze, text is scrolled horizontally across the display in a series of pauses and steps that resemble the natural fixations and saccades of reading. This method, along with rapid serial visual presentation, continuous scrolling, and static text, was presented on smart glasses to 23 participants with macular disease. Reading speed and subjective preference of the smart glasses was compared to reading text printed on paper using the participants’ habitual optical reading aid. Reading using smart glasses, the mean (±standard error) maximum reading speed was 122 ± 15 words per minute (wpm), compared to 74 ± 9 wpm using each participants’ habitual optical magnifier. This is a statistically significant difference as confirmed by a paired-sample t-test, t(17) = –4.61, p

The findings of this study can be used in the selection of the preferred retinal locus to establish better rehabilitation services such as eccentric viewing training for patients with age-related macular degeneration.The aim of this study was to determine the characteristics of the preferred retinal locus in native Persian-speaking patients with age-related macular degeneration.In this non-interventional case series, all patients with a diagnosis of age-related macular degeneration referred to the Retina Clinic of the Rassoul Akram Hospital, Tehran, Iran, were evaluated. The fixation characteristics were evaluated monocularly using the MP1 microperimeter (Nidek Technologies, Padua, Italy). Optical coherence tomography was used to determine the location of the central fovea. The images were overlaid and the preferred retinal locus-fovea distance was measured using Image J software.Fifty-one eyes of 35 patients with a mean age of 73.8 ± 7.7-years were evaluated in this study. Inferior-field, left-field, central-field, right-field, and superior-field preferred retinal locus were detected in 49 per cent, 33.3 per cent, 7.8 per cent, 5.9 per cent, and 3.9 per cent of the subjects, respectively. Fixation was stable in 70.6 per cent, relatively unstable in 15.7 per cent, and unstable in 13.7 per cent of the participants. Significant differences were not found in the mean values of logMAR visual acuity between different fields of the preferred retinal locus after Bonferroni correction (p = 0.031). Analysis of co-variance showed no significant difference in mean sensitivity values between different locations of the preferred retinal locus (p = 0.07). The mean preferred retinal locus-fovea distance was not significantly different between different fields of the preferred retinal locus (p = 0.063).Native Persian-speaking patients with central scotoma secondary to age-related macular degeneration place their self-selected preferred retinal locus most frequently in the inferior and left visual field, which would result in scotoma displacement to the superior and right visual field. Fixation stability was statistically similar in different locations of preferred retinal locus, but it improved with decreasing the preferred retinal locus-fovea distance.

Objective : To examine the effects of the eccentric viewing training software on reading and Activities of Daily Living(ADL) for individuals with central scotomas in Korea. Methods : A single-subject A-B-A research design for two low-vision individuals with central scotomas was used to examine the effects. The research was conducted over 14 sessions, which included three sessions during a pre-training baseline period (A), eight sessions during an intervention period to apply eccentric viewing training software on Korean character stimulation (B), and three sessions in a post-training baseline period (A). To measure reading and ADL, participants were assessed for their reading speed, Canadian Occupational Performance Measure(COPM), and Assessment of Motor and Process Skills(AMPS). Results : An Analysis of the data showed that the participants’ reading speed increased compared to their pre-training baseline scores, showing the highest level of increase in the first two to three sessions of training. The participants improved their performance in the reading-related activities, although a comparison of their overall ADL function pre-training and post-training showed no change. Conclusion : These findings suggest that the eccentric viewing training based on specific language characters, Korean, is an effective intervention method for improvement in the reading skills of individuals with central scotomas.

The purpose of this study is to develop PC Eccentric Viewing Training (EVT) and VR EVT Content, to conduct experiments to verify the validity of contents first through non-disabled people, and to compare and analyze VR and PC contents. Both PC and VR contents were produced with UNITY. This content model assumes that reducing inaccurate saccades by eliminating eye movement helps improve reading accuracy. In addition, the two contents are implemented in the same way as VR and PC versions. The content consists of two steps, both PC and VR. The purpose of the content is to improve reading accuracy by improving the fixation stability of Preferred Retinal Locus (PRL) and reducing inaccurate Saccades. The experiment consisted of 12 persons (within maximum visual acuity less than 0.3), and they were assigned to the PC Content group and VR Content group. The experiment was conducted a total of 5 times, except for two weeks, which is the time to adapt PRL. The experimental results showed that the reading accuracy of the VR content group was higher. In addition, When comparing VR contents with PC contents, the group that conducted the training through PC contents showed a decrease in concentration as it progressed to 1-3 steps, and the score distribution also fell overall. In conclusion, the study compared VR and PC contents, and the effectiveness of contents was verified through experiments.

SIGNIFICANCE This study explores whether eccentric viewing training (EVT) changes the properties of the retinal area used for fixation in subjects with bilateral macular disease. The data presented demonstrate the feasibility of conducting a randomized controlled trial on EVT. PURPOSE Patients with bilateral central scotomas adopt other retinal area(s) called preferred retinal locus to substitute the blind fovea. EVT is offered with the goal to improve functional vision by learning how to identify and use a more useful retinal area for fixation-a trained retinal locus-and/or to improve fixation stability with their existing preferred retinal locus. An observational study was conducted to determine whether patients change and adopt a new trained retinal locus location and/or if fixation stability improves after EVT. METHODS Seventy-six patients with bilateral central scotomas received EVT from an experienced rehabilitation therapist. Retinal locations for repeated fixations and sizes of central scotomas of the better eye were recorded before and after EVT with a scanning laser ophthalmoscope. The position and area of the 95% confidence bivariate ellipse that defines the retinal area in which 95% of fixations occur were analyzed. RESULTS We observed no significant difference between the size of the area of the fitted ellipses before (mean [SD], 26.4° [19.7°]) and after (mean [SD], 24.8° [20.9°]) EVT (P = .54). However, we observed a shift in the preferred retinal locus location after EVT (P < .0001). The mean (SD) shift in the position of the center of fixation after EVT was 7.5° (5.2°; range, 0.45 to 23°). This mean difference was larger than would be expected from average within-subject fixation stability. CONCLUSIONS The location of the retinal area used for fixation changes after EVT. Fixation stability does not change after EVT. These preliminary data are yet to be confirmed with the use of a control group.

Background: Eccentric viewing in macular disease has been described for half a century. However, a clear definition of eccentric viewing and preferred retinal locus (PRL) does not exist. Here, we determine how the PRL in macular disease is defined by researchers active in this field and, based on the responses received, propose a standardized definition of the preferred retinal locus.Method: A literature review of articles describing the PRL or eccentric viewing was performed. The first and senior authors of all identified publications were contacted and were asked to define the preferred retinal locus. Themes of responses were identified using inductive qualitative research techniques.Results: Frequently recurring themes related to the definition of the PRL included 1) it is a retinal area used for fixation, 2) it is task specific, 3) more than one PRL can be used, 4) it is a well-defined region of retina, and 5) the same PRL is used on repeated testing.Conclusion: Based on the responses received, a consensus definition of the PRL is proposed. It is suggested that researchers define the PRL carefully in experimental reports and an instrument that images the retina is used to define the location of the PRL. RETINA 31:2109-2114, 2011

Macular degeneration has a severe impact on a person's ability to perform activities of daily living. This study investigated the impact of in-home training in eccentric viewing on near acuity and performance of activities of daily living. The results suggest that eccentric viewing can ameliorate the impact of the loss of vision that is due to macular degeneration.

Purpose. Many parameters of visual performance (e.g., contrast sensitivity) are compromised under glaring light conditions. Recent data indicate that macular pigment (MP) is strongly related to improvements in glare disability and photostress recovery based on a filtering mechanism. In this study, we assessed the causality of this relation by supplementing lutein and zeaxanthin for 6 months while measuring MP, glare disability, and photostress recovery. Methods. Forty healthy subjects (mean age 23.9) participated in the study. Subjects were followed for 6 months and assessed at baseline, 1, 2, 4, and 6 months. Spatial density profiles of MP were measured using heterochromatic flicker photometry. Disability glare was measured using a 1 degree-diameter circular grating surrounded by a broadband glare source (a xenon-white annulus). The intensity of the annulus (11 degree inner and 12 degree outer diameters) was adjusted by the subject until the grating target was no longer seen. For the photostress recovery experiment, the time required to detect a 1 degree-diameter grating stimulus after a 5-s exposure to a 2.5 W/cm 2 , 5 degree-diameter disk was recorded. Subjects were tested under central viewing and eccentric viewing (10 degree temporal retina) conditions. Results. At the baseline time point, MP optical density (OD) at 30 eccentricity ranged from 0.08 to 1.04, and was strongly correlated with improved visual performance in the two glare tasks. After 6 months of lutein (L) and zeaxanthin (Z) supplementation, average MPOD (at 30 eccentricity) had increased from 0.41 to 0.57, and was shown to significantly reduce the deleterious effects of glare for both the visual performance tasks assessed. Conclusions. MP is strongly related to improvements in glare disability and photostress recovery in a manner strongly consistent with its spectral absorption and spatial profile. Four to 6 months of 12 mg daily L Z supplementation significantly increases MPOD and improves visual performance in glare for most subjects. (Optom Vis Sci 2008;85:82–88)

The loss of central vision subsequent to macular disease is often extremely debilitating. People with central field loss (CFL) must use other peripheral areas of the retina in order to see; areas with inferior resolution capacity, which are also affected by off-axis optical errors. The overall aim of the work encompassed by this thesis was to identify and evaluate methods of improving vision for people with CFL; with focus on the effects of off-axis optical correction and stimulus motion on resolution acuity and contrast sensitivity. Off-axis optical errors were measured using a commercially-available COAS-HD VR open-view aberrometer. We used adaptive psychophysical methods to evaluate grating resolution acuity and contrast sensitivity in the peripheral visual field; drifting gratings were employed to measure the effect of motion on these two measures of visual performance. The effect of sphero-cylindrical correction and stimulus motion on visual performance in healthy eyes and in subjects with CFL was also studied; in addition, the effect of adaptive optics aberration correction was examined in one subject with CFL. The COAS-HD aberrometer provided rapid and reliable measurements of off-axis refractive errors. Correction of these errors gave improvements in low-contrast resolution acuity in subjects with higher amounts of oblique astigmatism. Optical correction also improved high-contrast resolution acuity in most subjects with CFL, but not for healthy subjects. Adaptive optics correction improved both high and low contrast resolution acuity in the preferred retinal locus of a subject with CFL. The effect of stimulus motion depended on spatial frequency; motion of 7.5 Hz improved contrast sensitivity for stimuli of low spatial frequency in healthy and CFL subjects. Motion of 15 Hz had little effect on contrast sensitivity for low spatial frequency but resulted in reduced contrast sensitivity for higher spatial frequencies in healthy subjects. Finally, high-contrast resolution acuity was relatively insensitive to stimulus motion in the periphery. This thesis has served to broaden the knowledge regarding peripheral optical errors, stimulus motion and their effects on visual function, both in healthy subjects and in people with CFL. Overall it has shown that correction of off-axis refractive errors is important for optimizing peripheral vision in subjects with CFL; the use of an open-view aberrometer simplifies the determination of these errors. In addition, moderate stimulus motion can have a beneficial effect on contrast sensitivity for objects of predominantly low spatial frequency.

Purpose Technological devices such as smartphones and tablets are widely available and increasingly used as visual aids. This study evaluated the use of a novel app for tablets (MD_evReader) developed as a reading aid for individuals with a central field loss resulting from macular degeneration. The MD_evReader app scrolls text as single lines (similar to a news ticker) and is intended to enhance reading performance using the eccentric viewing technique by both reducing the demands on the eye movement system and minimising the deleterious effects of perceptual crowding. Reading performance with scrolling text was compared with reading static sentences, also presented on a tablet computer. Methods Twenty‐six people with low vision (diagnosis of macular degeneration) read static or dynamic text (scrolled from right to left), presented as a single line at high contrast on a tablet device. Reading error rates and comprehension were recorded for both text formats, and the participant's subjective experience of reading with the app was assessed using a simple questionnaire. Results The average reading speed for static and dynamic text was not significantly different and equal to or greater than 85 words per minute. The comprehension scores for both text formats were also similar, equal to approximately 95% correct. However, reading error rates were significantly (p = 0.02) less for dynamic text than for static text. The participants’ questionnaire ratings of their reading experience with the MD_evReader were highly positive and indicated a preference for reading with this app compared with their usual method. Conclusions Our data show that reading performance with scrolling text is at least equal to that achieved with static text and in some respects (reading error rate) is better than static text. Bespoke apps informed by an understanding of the underlying sensorimotor processes involved in a cognitive task such as reading have excellent potential as aids for people with visual impairments.

Eccentric reading techniques were taught to 20 subjects with central vision loss and absolute scotomas. Training was in a community based setting. On completion of training, subjects expressed an increased sense of independence and confidence along with the regained ability to perform many everyday-reading tasks.

The scanning laser ophthalmoscope (SLO) is an instrument of great value for observing viewing behaviour and characteristics of fixation in macula disorders; it also may have potential in assessing visual rehabilitation in affected individuals. It is important to understand the viewing strategies used by individuals with a central scotoma and eccentric fixation and to determine whether these strategies have changed as a result of any eccentric viewing training. We describe a method based on searching for multiple sectors in relative correspondence in consecutive SLO fundus images. In this method, successive fixation positions, and consequently viewing strategy, during the reading of isolated words and text passages can be extracted from SLO images. We found the maximum cumulative error in determining fixation position over 1000 consecutive frames to be 5 pixels (approximately 15 min arc) using fundus images from an individual with a macular lesion and clearly visible retinal features. The reconstruction of...

Purpose.: The detection of amblyopia in children relies on an accurate assessment of visual acuity. Visual deficits in anisometropic and strabismic amblyopia are different, but the influence of chart design, in particular position, and type of crowding features on visual acuity in the two types of amblyopia, is not clear. Certain aspects of amblyopic spatial vision are mimicked in healthy individuals by imposing increasing levels of blur and retinal eccentricity. We measured the effects of these conditions on visual acuity in healthy adults, with crowded and uncrowded vision tests. Methods.: Visual acuity was measured under conditions of blur (0–4 D) and eccentric viewing (0–5 degrees) using high-contrast optotypes derived from common children's acuity charts. Optotypes were presented in isolation, in commercially available crowded configurations, and in configurations with closer target-flanker separations than those currently available. Results.: Dioptric blur had similar degradative effects on crowded and isolated visual acuity (P > 0.05), whereas eccentric viewing resulted in a larger deterioration of visual acuity for crowded tests (E 2 of 0.86–1.06) than for isolated optotypes (E 2 of 1.57–1.72) (P < 0.05). Maximum crowding effects occurred for closer target-flanker separations than those currently used commercially. Conclusions.: In so far as blur and eccentric viewing mimic spatial acuity deficits in amblyopia, the results suggest that crowded tests might be of limited value in the detection of anisometropic amblyopia, but should be valuable in the detection of strabismic amblyopia. Crowding effects would be greater if flanking features were placed closer to the target than they currently are in commercially available charts.

Age-related macular degeneration (AMD) is the single most common cause of vision loss in people over the age of 50.1 Individuals with low vision caused by macular disease, experience severe difficulty with everyday tasks such as reading2 which has profound detrimental consequences for their quality of life.3 We have developed an app for the iPad (the MD_evReader) that aims to improve reading by enhancing the effectiveness of the eccentric viewing technique (EV) using dynamic text presentation (figure 1A). Eccentric viewing is a simple strategy adopted by individuals with AMD that involves using the relatively preserved peripheral region of their retina in order to see. A limiting factor of the EV technique is that it relies on the individual holding their gaze away from the focus of interest and suppressing the …

People who lose their central vision have to rely on their peripheral vision for all visual tasks. The ability to resolve fine details in the periphery is reduced due to retinal limitations and the optical aberrations arising from the use of off-axis vision. The aim of this work is to improve vision by enhancing the image quality at the preferred retinal locus by means of correcting the optical errors. The focus of this thesis has been to measure and correct peripheral optical errors, as well as to evaluate their impact on resolution acuity in both normal and central visual field loss subjects. In order to measure peripheral optics we employed a COAS HD VR open view aberrometer which is based on the Hartmann-Shack principle. Psychophysical methods were used to evaluate peripheral grating resolution acuity. We assessed the repeatability of the wavefront sensor in measuring the peripheral ocular aberrations. The symmetry of peripheral ocular aberrations between the left and right eyes was examined. The influence of age on peripheral ocular aberrations was also investigated. We evaluated peripheral vision with sphero-cylindrical correction in healthy eyes and performed the first adaptive optics aberration correction at the preferred retinal locus of a single central visual field loss subject. We found that the aberrometer was repeatable and reliable in measuring peripheral ocular aberrations. There was mirror symmetry between the two eyes for most of the peripheral aberration coefficients. Age had a significant influence on peripheral ocular aberrations; there were larger amounts of higher-order aberrations in old eyes than in young eyes. Peripheral low contrast resolution acuity improved with peripheral refractive correction in subjects who had higher amounts of off-axis astigmatism. Finally, adaptive optics aberration correction improved both high and low contrast resolution acuity measured at the preferred retinal locus of the single low vision subject. Because of their versatility, open view aberrometers will hopefully be a standard clinical instrument at low vision clinics as they allow for measurements to be rapidly performed at any location in the visual field. The existence of off-axis astigmatism should be better communicated within the low-vision rehabilitation community. Currently, the off-axis refractive errors can be corrected with conventional methods and we hope that the higher-order aberrations can also be corrected in a more realistic ways in the future. In conclusion, this thesis has shown that peripheral visual function can be improved by optical correction. The findings of this thesis have broadened the knowledge of peripheral optical errors and their influence on vision.

Prema Snelenu subnormalan vid podrazumeva svaku oštrinu vida ispod 1,0, uprkos najboljoj mogućoj optičkoj korekciji. Korekcija vida specijalnim optičkim pomagalima za subnormalan vid potrebna je osobama sa korigovanom oštrinom vida na boljem oku manjom od 0,3 (Min . of Are). Pomagala za subnormalan vid imaju ulogu da obezbede uvećanu i jasnu sliku posmatra nag predmeta na maku/i. Cilj istraživanja je utvrditi ulogu pomagala za subnormalan vid u podizanju kvaliteta života pacijenata i prikazati tehnike obuke pacijenata za njihovo korišćenje. Istraživanje je trajalo godinu dana (2011/2012) i obuhvatilo 50 pacijenta uzrasta od 7-60 godina sa korigovanom vidnom oštrinom na boljem oku manjom od 0,3. Svakom pacijentu je na osnovu detaljnog pregleda preporučeno odgovarajuće optičko pomagalo za subnormalan vid (teleskopi, hiperkorektivne prizmatične naočare, elektronska lupa ili zatvoreni televizijski sistem). Adaptacija na prepisana pomagalo trajala je četiri nedelje. Obuka je bazirana na: ekscentričnom gledanju (korišćenje ekstra fovea/nog dela makule), čitanju na kratkoj radnoj distanci,jakomfokalnom osvetljenju, vežbama koordinacija oko-ruka. Najčešći problem pacijenata u obavljanju svakodnevnih aktivnosti bila je nemogućnost čitanja. Tokom prve nedelje kod većine pacijenata zabeležena je sporost u čitanju (u proseku 15 reči u minuti) i oteža no izvođenje vežbi za ekscentrično gledanje. Nakon četiri nedelje obuke zabeležena je povećana brzina čitanja kod 48 pacijenata (96%), a 2 pacijenta (4%) nisu imala poboljšanje. Brzina čitanja kod 31 pacijenta {62%) se povećala sa 20 na 100 reči u minuti, kod njih 15 (30%) sa 15 na 90 reči u minuti, a 2 pacijenta (4%) su povećala brzinu sa 10 na 80 reči u minuti. Deca su brže napredovala od starijih pacijenata. Pacijenti sa subnormalnim vidom su kroz obuku naučili da uspešno koriste pomagala. Na taj način smo uticali da se brzina čitanja značajno poveća, a samim tim i poboljša kvalitet njihovog života. According to Snellen, subnormal vision means any visua/ acuity range below 1.0 despite the best possible optica/ correction. Vis ion correction by low vision aids is needed far patients with corrected visua/ acuity in the better eye oj le ss than 0.3 (Min. oj Are). The role oj /ow vision aids (telescopes, hyper-correction prismatic glasses, c/osed circuit video magnification systems) is to provide a c/ear magnified im age oj the observed object in the macu/a. The objective oj this arctic/e is to determine the role oj low vision aids in lije quality improvement oj patients and to show training techniques far their use. The study lasted one year (2011/2012) and inc/uded 50 patients aged 7-60 years with corrected visual acuity in the better eye oj less than 0.3. Appropriate low vision aid (telescopes, hyper-correction prismatic glasses, c/osed circuit video magnijication system, and e/ectronic magnijier) was recommended to each patient, based on detailed examination. Adaptation to the prescribed aid /asted four weeks. Training was based on: eccentric viewing (use oj extra-fovea/ pa rt oj the macu/a), reading on a short working distance, high faca/ lighting and exercise oj eye-hand coordination. The most common patients' problem in daily activities was the inability to read. During the first week with most oj the patients the slowness in reading (average 15 words per minute) and dijficulties in performing exercises far eccentric viewing were noticed. A/ter four weeks oj training increased reading speed has been noticed in 48 patients (96%) and 2 patients (4%) had no improvement. Reading speed in 31 patients (62%) has increased from 20 to 100 words per minute, with 15 oj them (30%) from 15 to 90 words per minute, and with 2 patients (4%) the speed has increased from 10 to 80 words per minute. Children had progressed faster than adult patients. Low vision patients have learned through training how to successfully use the aids. ln this way, we contributed to a significant increase oj reading speed and thus improved their quality oj lije.

Age-related macular degeneration (AMD) is the single most common cause of vision loss in people over the age of 501. Individuals with low vision caused by macular disease, experience severe difficulty with everyday tasks such as reading2, which has profound detrimental consequences for their quality of life3. We have developed an app for the iPad (the MD evReader) that aims to improve reading (of electronic books) by enhancing the effectiveness of the eccentric viewing technique (EV) using dynamic text presentation. Eccentric viewing is a simple strategy adopted by individuals with AMD that involves using the relatively preserved peripheral region of their retina in order to see. A limiting factor of the EV technique is that it relies on the individual holding their gaze away from the focus of interest and suppressing the natural and strong, tendency to make eye-movements (saccades). During normal reading, for example, a stereotypical pattern of horizontal saccades are made, from left-to-right, enabling fixations to be made on each word4 – Figure 1a). The natural inclination to make saccades is, however, difficult to suppress and limits the effectiveness of eccentric viewing in people with macular disease.

Purpose To quantify the effects of three vision rehabilitation training approaches on improvements in reading performance. Methods Thirty subjects with AMD participated in the training portion of the study. The median age of the subjects was 79 years (range, 54-89 years). The three training modules were: Visual Awareness and Eccentric Viewing (module 1), Control of Reading Eye Movements (module 2), and Reading Practice with Sequential Presentation of Lexical Information (module 3). Subjects were trained for 6 weekly sessions on each module, and the order of training was counterbalanced. All subjects underwent four assessments: at baseline and at three 6-week intervals. Reading performance was measured before and after each training module. A separate group of 6 subjects was randomly assigned to a control condition in which there was no training. These subjects underwent repeated assessments separated by 6 weeks. Results Reading speeds decreased by an average of 8.4 words per minute (wpm) after training on module 1, increased by 27.3 wpm after module 2, and decreased by 9.8 wpm after module 3. Only the increase in reading speed after module 2 was significantly different from zero. Sentence reading speeds for the control group, who had no reading rehabilitation intervention, was essentially unchanged over the 18 weeks (0.96 ± 1.3 wpm). Conclusions A training curriculum that concentrates on eye movement control increased reading speed in subjects with AMD. This finding does not suggest that the other rehabilitation modules have no value; it suggests that they are simply not the most effective for reading rehabilitation.

Purpose: The definition of eccentric viewing (EV) is using non-foveal preferred retinal loci (PRL) for viewing. The purpose of the present study was to investigate the clinical effect of EV training for low vision rehabilitation in patients with central scotomas. Methods: The direction of EV was monitored in 30 low vision patients with central scotomas by moving the patient’s view. The PRL was found by using a direct ophthalmoscope and retinal camera; the preserved visual field was identified using a kinetic visual field analyzer. The relationships between EV, PRL, and visual field were evaluated. The patients and their guardians were educated regarding EV. After 2 weeks of self-training, maintenance of EV was checked and changes in best-corrected visual acuity (BCVA), reading speed, and satisfaction questionnaire were evaluated. Results: A relationship between EV, PRL, and visual field was in accordance in half of the patients. There were no significant differences in demographics and basic visual characteristics in patients where the relationship was not in accordance. EV was maintained in two-thirds of the patients, but there were no significant differences in demographics and basic visual characteristics in patients who discontinued EV. There were no significant improvements in BCVA; however, reading speed and the satisfaction scores increased significantly with EV. Conclusions: The direction of EV was effectively detected by convenient access using an inexpensive method. Functional vision and satisfaction significantly improved following EV training. EV training can be used as an effective method for low vision rehabilitation in patients with central scotomas.

Several areas related to the use of telescopes in low vision are reviewed. These include: contrast sensitivity function; eccentric viewing through a telescope; field of view; telescope used in reverse; and IOL-spectacle lens telescopic systems. Experimental data are included to support selected clinical observations routinely made by low vision clinicians.

Adaptation to eccentric viewing in subjects with a central scotoma remains poorly understood. The purpose of this study was to analyze the adaptation stages of oculomotor control to forced eccentric reading in normal subjects.Three normal adults (25.7 +/- 3.8 years of age) were trained to read full-page texts using a restricted 10 degrees x 7 degrees viewing window stabilized at 15 degrees eccentricity (lower visual field). Gaze position was recorded throughout the training period (1 hour per day for approximately 6 weeks).In the first sessions, eye movements appeared inappropriate for reading, mainly consisting of reflexive vertical (foveating) saccades. In early adaptation phases, both vertical saccade count and amplitude dramatically decreased. Horizontal saccade frequency increased in the first experimental sessions, then slowly decreased after 7 to 15 sessions. Amplitude of horizontal saccades increased with training. Gradually, accurate line jumps appeared, the proportion of progressive saccades increased, and the proportion of regressive saccades decreased. At the end of the learning process, eye movements mainly consisted of horizontal progressions, line jumps, and a few horizontal regressions.Two main adaptation phases were distinguished: a "faster" vertical process aimed at suppressing reflexive foveation and a "slower" restructuring of the horizontal eye movement pattern. The vertical phase consisted of a rapid reduction in the number of vertical saccades and a rapid but more progressive adjustment of remaining vertical saccades. The horizontal phase involved the amplitude adjustment of horizontal saccades (mainly progressions) to the text presented and the reduction of regressions required.

Low vision may affect a person's learning, daily functioning, and psychosocial status. Intervention in the form of vision rehabilitation has enabled many people to successfully meet and overcome the challenges posed by low vision. Part one of this two-part feature presented a four-phase, interdisciplinary model of low vision services that can be applied to any setting. This paper (part two) focuses on methods of assessing low vision, providing clinical services, and establishing an adaptive training and instructional program. The collaborative relationship between the patient/client, low vision physician (optometrist or ophthalmologist), and allied health professional (specifically, the occupational therapist) is described.

For people with central visual field loss, eccentric vision is all that they have to rely on. Even for those who learn how to correctly utilize their eccentric vision, it will never be as good as the central for two entirely different reasons: the off-axis optics of the eye can result in large refractive errors, and the low function of the peripheral retina. This thesis deals with the first of these factors: how to study and correct the eccentric aberrations in people with low vision by measuring the optics of their eyes, correcting the aberrations, particularly astigmatism, and evaluating improvements in visual functions. The individual variations are large for both astigmatism and higher order aberrations such as coma. The main results of this research show that visual improvements through eccentric corrections are possible in spite of the retina’s poor function outside of the macula. Eccentric optical correction affects both resolution and detection capacities. A person’s visual ability can also be influenced by their awareness and training of eccentric viewing. För människor med centrala skotom är den excentriska synen den enda som finns att tillgå. Också för den som lär sig att använda sin excentriska syn är denna sämre än den centrala synen, och det av två helt olika skäl: att ögonoptiken kan ge stora avbildningsfel excentriskt respektive att näthinnan utanför makula har en lägre funktion. Denna avhandling handlar om den första av dessa faktorer: hur man kan studera och korrigera de excentriska avbildningsfelen hos synsvaga människor genom att mäta deras ögonoptik, korrigera avbildningsfelen, speciellt astigmatismen, samt utvärdera förbättringen i synfunktionerna. De individuella variationerna är stora. Det gäller både astigmatismen och högre ordningens aberrationer, t.ex. koma. Arbetets huvudresultat är att synförbättringar genom excentriska optiska korrektioner är möjliga trots näthinnans betydligt sämre funktion utanför makula. Excentrisk optisk korrektion påverkar både upplösningsförmåga och detektionsförmåga. Synförmågan påverkas också av medvetandegörande och träning av excentrisk fixation. Sammantaget öppnar avhandlingen ett stort forskningsområde, särskilt viktigt när andelen äldre nu växer och det därför tillkommer fler människor med makuladegeneration. Förhoppningen är att det ska gå att utveckla fler och bättre mätmetoder och optiska korrektioner för excentrisk syn samt att det skall gå att studera separata delar av synfunktionen närmare, för att därigenom få en ökad förståelse för hur olika ögonsjukdomar påverkar olika synförmågor. Det är också viktigt att undersökningarna och förbättringarna framöver berör fler människor än de med stora centrala skotom och medveten excentrisk fixation samt att resultaten finner sin tillämpning i klinisk verklighet.

We conducted three experiments in order to examine the influence of gaze behavior and fixation on audiovisual speech perception in a task that required subjects to report the speech sound they perceived during the presentation of congruent and incongruent (McGurk) audiovisual stimuli. Experiment 1 showed that the subjects' natural gaze behavior rarely involved gaze fixations beyond the oral and ocular regions of the talker's face and that these gaze fixations did not predict the likelihood of perceiving the McGurk effect. Experiments 2 and 3 showed that manipulation of the subjects' gaze fixations within the talker's face did not influence audiovisual speech perception substantially and that it was not until the gaze was displaced beyond 10 degrees - 20 degrees from the talker's mouth that the McGurk effect was significantly lessened. Nevertheless, the effect persisted under such eccentric viewing conditions and became negligible only when the subject's gaze was directed 60 degrees eccentrically. These findings demonstrate that the analysis of high spatial frequency information afforded by direct oral foveation is not necessary for the successful processing of visual speech information.

Background:The main optical effect of an ophthalmic prism is to deviate uniformly the entire field of view seen through the prism, resulting in an equal eye movement, if fixation on the same object is to be maintained. Conversely, it has been suggested that, in the case of low vision due to central scotoma, the eye changes its eccentric viewing behaviour when a prism is introduced, that is, the eye remains stationary with a change of retinal image location. Method:A new method is described in which retinal image position was recorded with a confocal scanning laser ophthalmoscope in four experimental conditions. Results:Results showed that the normally-sighted eye rotates rapidly to compensate for the introduction of a prism. Conclusion:Future studies are required involving subjects with central scotoma but it is likely that many subjects with low vision will also refixate behind a prism and that the prescribing and wearing of bilateral prism in cases of central vision loss will have limited effectiveness in the demonstration or training of eccentric viewing.

The influence of visual fixation position and stimulus size on the scalp-recorded "vertex positive peak" (VPP) evoked by images of faces was studied in three subjects. Responses were recorded, in turn, for line-drawn, frontal-view faces of approximately 8, 4, 2, and 1 deg length, fixated at the centre (bridge of the nose), and at points 1, 2, 3, and 4 deg to the left and right, and above and below, centre. The results showed that central fixation produced VPPs of similar, maximal amplitude for all face sizes. By comparison, "on-face" eccentric viewing yielded attenuated and delayed responses, and the degree of response attenuation as a function of eccentricity was directly related to the face size, with similar amplitude responses being evoked for corresponding fixation locations on each face. Very small or no VPPs were recorded for most "off-face" fixations. Similar results were observed for profile faces, except that the maximal VPP was recorded for fixations near the eyes and not in the centre of the head, and almost identical VPPs were evoked by a centrally fixated face presented with and without an adjacent face or object. These response properties, which correspond to the subjective perception of the facial stimuli, suggest that the VPP reflects brain mechanisms optimized to respond to single, fixated faces, irrespective both of facial image size and of the presence of neighbouring figures.