Habitual Vision Research Articles

Visual Status in Children with Dyslexia at the Integrated Special Education Program in Selangor, Malaysia

Objective: Dyslexia is a learning disorder, characterized by difficulties in recognizing, decoding, and spelling words. Studies on visual status of individuals with dyslexia have yielded mixed findings. This study aimed to assess visual acuity and refractive errors in dyslexic children in Selangor, Malaysia.Material and Methods: A cross-sectional study was conducted in the integrated special education program (PPKI) for secondary schools across three randomly selected districts in Selangor. Children with dyslexia from 15 schools were enrolled. Distance and near visual acuity were measured, and non-cycloplegic refraction was performed to identify refractive errors. Descriptive analysis was used to describe the distribution of visual acuity and refractive errors. The Wilcoxon Signed-Rank test was used to compare habitual and corrected visual acuity (VA).Results: 137 dyslexic children, aged 13 to 19 years, participated in the study. 60% of the participants had good habitual distance VA. Meanwhile, the percentage of good habitual near VA were higher than distance VA. The Wilcoxon Signed-Rank test showed that corrected VA was significantly better than habitual VA. The most common ametropias observed were myopia and astigmatism.Conclusion: Dyslexic children in the PPKI program generally have good visual acuity and are emmetropic. However, uncorrected refractive error and suboptimal optical refraction were the primary causes of unsatisfactory habitual vision in some children. Findings highlight the need to screen for refractive errors and provide appropriate optical correction to this population to prevent further hindrance to their reading ability.

Status of Vision and Eye Care Among Patients in Rehabilitation Hospital Units: A Cross-Sectional Study

ObjectivesThe prevalence of vision disorders is high among geriatric and hospital inpatient populations, yet they often go undetected, resulting in consequences such as falls or prolonged recovery time. A needs assessment study was conducted to investigate levels of vision and the potential prevalence of unmanaged/undiagnosed ocular disorders among adult inpatients in a hospital-based rehabilitation unit. DesignCross-sectional study. Setting & ParticipantsInpatient rehabilitation units of an acute care hospital system in Ontario, Canada. Adults (n = 112) in a hospital inpatient rehabilitation unit participated from October 2018 to February 2019. MethodsParticipants were surveyed regarding their demographic, ocular, and medical data and spectacle wear. Visual acuity, contrast sensitivity, visual fields, and stereoacuity plus the spectacle condition were directly assessed. ResultsThe majority (75%) were found to have reduced habitual vision while in hospital. Nearly 60% of participants reported at least some difficulty reading a newspaper or distinguishing a face or were “not happy with their vision.” This was despite 80% of participants reporting that they had an eye care practitioner and 70% that they had an eye examination within the last 2 years. More than half (51.8%) of the participants received the recommendation to follow up with their eye care practitioner on discharge from the hospital. Conclusions and ImplicationsReduced vision and vision disorders has a high prevalence among hospital patients in rehabilitation units and should be evaluated at or soon after hospital intake. By incorporating vision screening tools, necessary precautions may be taken to avoid possible falls and promote recovery.

How Is Jump Performance Affected in Male Athletes when Completed with a Visual Impairment?

High-, long-, and triple-jump athletic events may need to consider whether it is appropriate to group vision-impaired athletes in the same classification with loss of different visual functions, and a greater emphasis may need to be placed on the visual field (VF) within the current classification system used. Athletes with vision impairment are grouped, based on their visual function, into one of three different classes (B1, B2, and B3, with B1 being the most severe). Athletes in class B2 have loss in visual acuity (VA; range, 1.50 to 2.60 logMAR) or VF (constricted to a diameter of <10°). The current study investigated how loss of different visual function (VA or VF) within the same class impacts jumping performance, a fundamental component in long-, triple-, and high-jump athletic events. Ten subelite male athletes (age, 21.6 ± 0.96 years; height, 178.8 ± 2.97 cm; mass, 82.2 ± 10.58 kg) with normal vision who participate in athletics were recruited. Participants completed drop jumps in four vision conditions: habitual vision condition (Full), VA no better than 1.60 logMAR (B2-VA), VF restricted to <10° (B2-VF), and VA no better than 1.30 logMAR (B3-VA). Meaningful differences were observed between Full and B2-VF conditions. After rebound, vertical velocity at take-off was highest in Full condition (2.84 ± 0.35 m · s-1; 95% confidence interval [CI], 2.68 to 2.99 m · s-1) and was lowest in B2-VF condition (20% reduction; 2.32 ± 0.29 m · s-1; 95% CI, 2.16 to 2.48 m · s-1). Peak vertical jump height was highest in Full (0.42 ± 0.10 m; 95% CI, 0.38 to 0.46 m) and reduced by 40% in B2-VF (0.28 ± 0.07 m; 95% CI, 0.24 to 0.32 m). Minimal differences were found between Full and B2-VA, or B3-VA conditions. Jump performance is compromised in athletes with simulated vision impairment. However, decrements in performance seem specific to those with severely constricted VF. Those with reduced VA (in B2-VA and B3-VA classes) seem to produce performance comparable to those with normal vision.

Habitual visual acuity in a large urban cohort of Western India and factors influencing poor habitual vision.

Purpose:The aim of this study was to determine habitual visual acuity (HVA) in a large urban cohort in western India and identify factors associated with poor HVA.Methods:This was a prospective study conducted over 10 days in September 2018 to assess the HVA in individuals attending a 10-day festival in Western India. Participants who volunteered to undergo vision screening and also filled the questionnaire form pertaining to demographic information including their age, gender, address, income, and educational status were included in this study. HVA was recorded with the distance correction that the participants were wearing when they attended the screening. The study evaluated the prevalence of visual acuity 6/6 or <6/6, 6/12, and 6/18 and the factors associated with lower visual acuity.Results:Of the 6300 participants, 1660 (26.3%) were females. Majority of the participants were from urban background (6084, 96.6%) and were of younger age group (18–40 years––3786, 60.1%; 41–60 years––2187, 34.7%; >60 years––327, 5.2%). HVA was recorded as 6/6 both eyes in 4136 (65.6%), at least 6/12 both eyes in 5691 (90.3%), and at least 6/18 both eyes in 5974 (94.8%) individuals. Only 11 patients (0.17%) had VA worse than 6/60 with only 3 patients (0.003%) having bilateral VA <6/60. Older age, female sex, lower education status, and low annual income were significant risk factors for poor HVA.Conclusion:Poor education, lower income, female gender, and old age are significantly associated with poor HVA even in urban Western India despite relatively easy access to affordable eye care facilities.

The Effect of Simulated Central Field Loss on Street-crossing Decision-Making in Young Adult Pedestrians.

This study explored the street-crossing decision-making performance of young normally sighted subjects with simulated central field loss (CFL). The results suggest that using eccentric viewing enables a person to make safe and reliable street-crossing decisions. This study tested the hypothesis that, as the diameter of an experimentally induced central scotoma increases, the accuracy and reliability of street-crossing decisions worsen. Street-crossing decisions were measured in 20 young subjects aged between 23 and 31 years while monocularly viewing a nonsignalized, one-way street for different vehicular arrival times. Using a 5-point rating scale, subjects judged whether they could cross the street before vehicular arrival with habitual vision and simulated CFL with eccentric viewing. The CFL was induced using soft contact lenses with different central opaque diameters. Using receiver operating characteristic curve analysis, we obtained subjects' accuracy (amount of time in seconds where subjects either overestimated or underestimated vehicular arrival time relative to their actual crossing time) and reliability (how quickly subjects transitioned from judging insufficient to sufficient time to cross relative to their actual crossing time). The centrally opaque contact lenses induced central scotomata with a mean (standard deviation) diameter of 17.12° (5.83°). No significant difference in street-crossing accuracy (P = .35) or reliability (P = .09) was found between the normal, habitual vision and simulated CFL conditions. No statistically significant correlations were found between scotoma diameter and the accuracy and reliability of subjects' street-crossing decisions (P = .83 and P = .95, respectively). The findings of this study suggest that adopting eccentric viewing enables a person to successfully mitigate the negative effects of an absolute central scotoma on the accuracy and reliability of their street-crossing decisions.

Unmanned Aerial vehicle’s runway landing system with efficient target detection by using morphological fusion for military surveillance system

In the surveillance of military system Unmanned Ariel vehicles (UAV’s) offers a remarkable service. Software Defined Network (SDN) is one of approach for UAV for improving target localization with surveillance for many applications . One of the critical issues for an Unmanned Ariel vehicles (UAV’s) landing is the detection of runway in a low visibility conditions with computer vision. Also, the key problem is the accurate and robust detection of runway. A method of runway detection for fixed wing UAVs with a forward-looking camera is uses sensor based communication in network framework between source (UAV’S) and destination (runway sensor). Yet, this depends on the technical experience for landing an UAV’s safely. Nowadays, highly advanced equipments are being developed for improving safety and transportation system to handle the problem of landing under low visibility conditions. However, natural or habitual vision could be reduced during low visibility situations. This may be due to many meteorological factors like haze, darkness, fog etc. From the discussion made in this paper, the authors mainly concentrate on managing an aircraft system under low luminosity condition during the landing. In this research, effective Morphological fusion method is employed for the prediction of virtual runway imagery to avoid accident landing process. For this, fusion of sensor data for DEM (Digital Elevation Map) Data, infrared image (IR) and navigation parameter are used. The performance of this research using Morphological fusion method gives a fused image of the runway prediction for UAV’s under poor visibility condition. After obtaining the fused image, it is involved in ROI (Region of Interest) contour tracing process to get the clear location of landing of an UAV’s without harm. The virtual imaginary model can be produced through contour tracing to predict runway. By this method, a less prediction time or setting time is achieved and maximum accuracy is obtained through simulation using MATLAB tool. Finally, the proposed experimental outcomes are compared with the existing technology. The proposed approach will be use in aircraft sensor based communication between the network (source to destination) to detect the target and to provide a better surveillance for military applications.

Vision screening at two years does not reduce the prevalence of reduced vision at four and a half years of age

BackgroundThere is currently insufficient evidence to recommend vision screening for children < 36-months of age. This study assessed the effect of comprehensive vision screening, as well as the sensitivity of age‐appropriate vision tests, at two years of age on habitual visual acuity at 4.5-years of age.MethodsChildren born at risk of neonatal hypoglycaemia (n = 477) underwent vision assessment at 54 ± 2-months of age including measurement of monocular and binocular habitual visual acuity, assessment of binocularity and stereopsis. Of these children, 355 (74.4 per cent) had also received vision screening at two years of age (mean age = 24± 1-months), while 122 were not screened.ResultsEighty (16.8 per cent) children were classified as having reduced vision at 4.5-years of age, but the prevalence of reduced vision did not differ between children who had previously been screened at two years of age and those who had not (15.5 per cent versus 20.5 per cent, p = 0.153). However, children with reduced vision at 4.5-years of age were more likely to have had visual abnormalities requiring referral detected at two years of age (p = 0.02). Visual acuity and mean spherical equivalent autorefraction measurements were also worse (higher values) in two‐year‐old children who were later classified with reduced habitual visual acuity (p = 0.031 and p = 0.001, respectively). Nevertheless, unaided binocular visual acuity, non‐cycloplegic refractive error, and stereopsis at two years all showed poor sensitivity and specificity for predicting visual outcomes at 4.5-years of age.ConclusionOur findings do not support the adoption of early vision screening in children as current vision tests suitable for use with two‐year‐old children have poor sensitivity for predicting mild–moderate habitual vision impairment at 4.5-years of age.

Contrast Sensitivity Is a Significant Predictor of Performance in Rifle Shooting for Athletes With Vision Impairment.

Purpose: In order to develop an evidence-based, sport-specific minimum impairment criteria (MIC) for the sport of vision-impaired (VI) shooting, this study aimed to determine the relative influence of losses in visual acuity (VA) and contrast sensitivity (CS) on shooting performance. Presently, VA but not CS is used to determine eligibility to compete in VI shooting.Methods: Elite able-sighted athletes (n = 27) shot under standard conditions with their habitual vision, and with their vision impaired by the use of simulation spectacles (filters which reduce both VA and CS) and refractive blur (lenses which reduce VA with less effect on CS). Habitual shooting scores were used to establish a cut-off in order to determine when shooting performance was ‘below expected’ in the presence of vision impairment. Logistic regression and decision tree analyses were then used to assess the relationship between visual function and shooting performance.Results: Mild reductions in VA and/or CS did not alter shooting performance, with greater reductions required for shooting performance to fall below habitual levels (below 87% of normalized performance). Stepwise logistic regression selected CS as the most significant predictor of shooting performance, with VA subsequently improving the validity of the model. In an unconstrained decision tree analysis, CS was selected as the sole criterion (80%) for predicting ‘below expected’ shooting score.Conclusion: Shooting performance is better predicted by losses in CS than by VA. Given that it is not presently tested during classification, the results suggest that CS is an important measure to include in testing for the classification of vision impairment for athletes competing in VI shooting.

The Level of Vision Necessary for Competitive Performance in Rifle Shooting: Setting the Standards for Paralympic Shooting with Vision Impairment.

The aim of this study was to investigate the level of vision impairment (VI) that would reduce performance in shooting; to guide development of entry criteria to visually impaired (VI) shooting. Nineteen international-level shooters without VI took part in the study. Participants shot an air rifle, while standing, toward a regulation target placed at the end of a 10 m shooting range. Cambridge simulation glasses were used to simulate six different levels of VI. Visual acuity (VA) and contrast sensitivity (CS) were assessed along with shooting performance in each of seven conditions of simulated impairment and compared to that with habitual vision. Shooting performance was evaluated by calculating each individual’s average score in every level of simulated VI and normalizing this score by expressing it as a percentage of the baseline performance achieved with habitual vision. Receiver Operating Characteristic curves were constructed to evaluate the ability of different VA and CS cut-off criteria to appropriately classify these athletes as achieving ‘expected’ or ‘below expected’ shooting results based on their performance with different levels of VA and CS. Shooting performance remained relatively unaffected by mild decreases in VA and CS, but quickly deteriorated with more moderate losses. The ability of visual function measurements to classify shooting performance was good, with 78% of performances appropriately classified using a cut-off of 0.53 logMAR and 74% appropriately classified using a cut-off of 0.83 logCS. The current inclusion criteria for VI shooting (1.0 logMAR) is conservative, maximizing the chance of including only those with an impairment that does impact performance, but potentially excluding some who do have a genuine impairment in the sport. A lower level of impairment would include more athletes who do have a genuine impairment but would potentially include those who do not actually have an impairment that impacts performance in the sport. An impairment to CS could impact performance in the sport and might be considered in determining eligibility to take part in VI competition.

Vision and driving status of older Australians with cataract: an investigation of public hospital waiting lists

BackgroundAlthough cataract surgery can restore sight, lengthy waiting times are common in public hospitals in Australia. We investigated the driving status of older people during their surgical waiting period.MethodsBaseline, cross‐sectional data from two prospective cohort studies of patients aged 50-years and older on Australian public hospital cataract surgery waiting lists were analysed. Participants underwent assessment of vision and completed the Driving Habits Questionnaire. The vision status was compared between current drivers and former drivers.ResultsParticipants (n = 442) were on average 73 ± 8-years of age and approximately half were women (229/442, 52 per cent). Habitual vision was 6/12+2 on average (0.26 ± 0.21 logMAR). There were 263 (60 per cent) current drivers, 110 (25 per cent) former drivers and 69 participants (16 per cent) who had never driven. Among the current drivers, 82/263 (31 per cent) failed visual acuity requirements for an unconditional drivers’ license (6/12 acuity with one or both eyes). The former drivers had worse visual acuity than the current drivers (between group difference 0.12 ± 0.20 logMAR, p < 0.0001) and worse contrast sensitivity (between group difference −0.14 ± 0.22 log units, p < 0.0001). Both high contrast visual acuity and contrast sensitivity were independently associated with still driving. More than half (140/263, 53 per cent) of the drivers believed that their cataract had affected their driving and 23 current drivers (nine per cent) reported a crash in the last 12-months.ConclusionWe report on the level of visual impairment among older drivers waiting for cataract surgery. Approximately one‐third did not meet the required visual acuity standard for driving and hence would require further ophthalmic assessment and a conditional license to continue to drive. Approximately one‐quarter of the surgical candidates were no longer driving and this was associated with greater visual impairment. These findings support a need for timely and appropriately prioritised access to cataract surgical services.

Depressive symptoms in older adults awaiting cataract surgery.

To assess the prevalence and predictors of depressive symptoms in a cohort of older adults awaiting cataract surgery and establish threshold vision at which depressive symptoms may emerge. Analysis of cross-sectional baseline data from a longitudinal cohort study of patients aged ≥65 years on Australian public hospital cataract surgery waiting lists. We included 329 participants enrolled October 2013-August 2015. Participants completed assessment of depressive symptoms, visual disability, quality of life, social participation and exercise frequency at least one month prior to cataract surgery. High and low contrast habitual vision was examined and systemic comorbidities noted. Depressive symptoms prior to first eye cataract surgery. The prevalence of depressive symptoms was 28.6% (94/329). Univariate analysis identified that participants with poorer high contrast vision, reduced quality of life, greater patient-reported visual disability, higher comorbidity score and who were taking more medications were more likely to exhibit signs of depression. Greater patient-reported visual disability (P = 0.02), reduced quality of life (P = 0.003) and a higher comorbidity score (P = 0.02) remained significantly associated with depressive symptoms in the multivariable model. Depressive symptoms emerged at a visual acuity of 6/12. These findings demonstrate a high prevalence of depressive symptoms in older persons with cataract, emerging at modest levels of vision loss. Efficient referral processes, timely surgical management, and improved screening and coordinated treatment of depressive symptoms during the surgical wait may minimize the negative psychological effects of cataract in this already vulnerable population.

Symptomatic vergence disorders in junior high school children in Ghana

Background: Optometrists in Ghana are hampered in performing comprehensive binocular vision assessments, because of the lack of appropriate instruments leading to a paucity of data on vergence disorders and their association with asthenopia among Ghanaian school children.Aim: To establish the prevalence of symptomatic vergence disorders among junior high school (JHS) children in Cape Coast Metropolis, Ghana, in their habitual (vision) states and investigate if there were any associations between these disorders and specific asthenopic symptoms.Methods: A prospective cross-sectional school-based study using a multistage sample of 627 participants aged 12–17 years from JHSs in Cape Coast Metropolis. Participants completed a reliable asthenopic symptoms questionnaire and 220 participants who expressed two or more severe or very severe symptoms were selected for comprehensive binocular vision assessment in their habitual vision state.Results: The prevalence of symptomatic vergence disorders among JHS children in Cape Coast Metropolis was 14.8%. For specific symptomatic vergence disorders, the prevalence was: 1.4% basic esophoria, 1.4% basic exophoria, 8.6% convergence insufficiency, 1.8% convergence excess, 0.8% fusional vergence dysfunctions and 0.8% divergence excess. No participant had symptomatic divergence insufficiency. The study revealed significant associations between some specific symptomatic vergence disorders and specific asthenopic symptoms even though all of these asthenopic symptoms overlapped in other vergence disorders.Conclusion: Presenting complaints of specific asthenopic symptoms does not differentiate between specific types of vergence disorders. A comprehensive binocular vision assessment is vital in the diagnosis and management of these disorders to relieve asthenopia.

Symptomatic accommodative disorders and asthenopia: Prevalence and association in Ghanaian children

Background: There is a scarcity of data on asthenopia and accommodative disorders in children in Ghana as optometrists sometimes fail to carry out comprehensive assessments because of the lack of appropriate instruments.Aim: To establish the prevalence of asthenopic symptoms and symptomatic accommodative disorders among Junior High School children in Cape Coast metropolis (in their habitual vision state) and to investigate if there are any associations between asthenopic symptoms and the disorders.Method: A prospective cross-sectional school-based study using a multistage sample of 627 participants aged 12–17 years from Junior High Schools in Cape Coast metropolis, Ghana, was conducted. Participants completed a reliable asthenopic symptoms questionnaire (Cronbach’s α = 0.866), and 220 participants who expressed two or more severe or very severe symptoms were selected for comprehensive accommodative system assessment over their habitual vision state.Results: The prevalence of symptoms of asthenopia (two or more severe or very severe) and symptomatic accommodative disorders were 35.1% and 17.4% respectively. For specific symptomatic accommodative disorders, the prevalence was as follows: 7.7% accommodative insufficiency, 4.5% accommodative infacility, 1.4% accommodative excess and 3.8% accommodative fatigue. There were significant associations between some specific accommodative disorders and some specific asthenopic symptoms even though these asthenopic symptoms overlapped in other accommodative disorders.Conclusion: Specific asthenopic symptoms do not discriminate between the presences of specific types of accommodative disorders. A comprehensive accommodative system assessment with appropriate instruments is relevant to the diagnosis and management of accommodative disorders to relieve asthenopic symptoms.

Refractive Errors among Administrative Staff of Senior High Schools in the Kumasi Metropolis

Introduction: Studies in other parts of the world show refractive error as a notable cause of visual impairment. Ghana is not an exception to these findings. Objective: This study focused on determining the types and prevalence of refractive errors among administrative staff of selected senior high schools in the Kumasi Metropolis of Ghana.Methods: A descriptive cross-sectional study in which 120 administrative staff from 10 randomly selected public senior high schools was conducted. Information collected from participants included demographics and ocular and medical history. Eye health assessment included visual acuity, examination of external eye structures, direct ophthalmoscopy, and refraction. Refractive error diagnosis was made in the event of pinhole acuity being better than participant’s habitual vision in either eye or both. Descriptive statistics was employed and a p-value<0.05 was considered significant for the study.Results: Oculo-visual symptoms reported included teary eyes, headache, blur vision and double vision. The overall prevalence of refractive error was 30.8%; hyperopia, myopia, and astigmatism with prevalence figures of 17.5%, 10.8% and 2.5% respectively.Conclusion: The prevalence of refractive error was considerably high among this group of workers. These workers would benefit from vision screening programmes and refractive error correction if made available to them.

Relationship between Vision and Visual Perception in Hong Kong Preschoolers

Although superior performance in visual motor and visual perceptual skills of preschool children has been documented in the Chinese population, a normative database is only available for the US population. This study aimed to determine the normative values for these visuomotor and visual perceptual tests for preschool children in the Hong Kong Chinese population and to investigate the effect of fundamental visual functions on visuomotor and visual perceptual skills. One hundred seventy-four children from six different kindergartens in Hong Kong were recruited. Distance visual acuity, near visual acuity, and stereopsis were tested, along with two measures of visual perception (VP): Visual-Motor Integration (VMI) and Test of Visual-Perceptual Skills (TVPS). Raw VMI and TVPS scores were converted into standard/scaled scores. The impact of basic visual functions on VP (VMI and TVPS) was examined using multiple regression. Visual functions were generally good: only 9.2 and 4.6% of subjects had unilateral and bilateral reduced habitual vision, respectively (distance visual acuity in the better eye >0.3 logMAR [logarithm of the minimum angle of resolution]). Performance in the VMI and in the visual memory and spatial relationships subtests of the TVPS exceeded that reported for age-matched children from the United States. Multiple regression analysis provided evidence that age had the strongest predictive value for the VMI and VP skills. In addition, near visual acuity was weakly associated with performance in the VMI and the visual discrimination and spatial relationships subtests of the TVPS, accounting for a limited proportion of the intersubject variability (R < 3%; p < 0.001). Hong Kong preschoolers outperformed their US peers in the VMI and visual memory/spatial relationships of TVPS subtests, perhaps attributed to greater exposure to such material during their preschool home education. This study provided normality data for VMI and four subtests of the TVPS for Hong Kong Chinese preschool children as a reference for future studies.

Increase in Visibility of Light Signals

This work describes a study of perception of light signals used in aeronautics. Devices known as “obstruction light” (L-810 type, according to the Organization of International Civil Aviation OACI and the Federal Aviation Administration FAA) with LED technology were fed with square pulses of voltage, attaining flashes with imperceptible rise times. The lights were presented to observers, simulating the habitual vision conditions for these devices. With this diagram, perceptive comparisons for different flash frequencies were carried out, exploring especially the transition zone between flickering and steady vision of light. The test showed that an important number of people experienced a perceptive increase in such transition zone. The phenomenon, which can be related with to Broca-Sulzer effect, could be used in order to improve the signal visibility.

How Do Vision and Hearing Impact Pedestrian Time-to-Arrival Judgments?

To determine how accurate normally sighted male and female pedestrians were at making time-to-arrival (TTA) judgments of approaching vehicles when using just their hearing or both their hearing and vision. Ten male and 14 female subjects with confirmed normal vision and hearing estimated the TTA of approaching vehicles along an unsignalized street under two sensory conditions: (1) using both habitual vision and hearing and (2) using habitual hearing only. All subjects estimated how long the approaching vehicle would take to reach them (i.e., the TTA). The actual TTA of vehicles was also measured using custom-made sensors. The error in TTA judgments for each subject under each sensory condition was calculated as the difference between the actual and estimated TTA. A secondary timing experiment was also conducted to adjust each subject's TTA judgments for their "internal metronome." Error in TTA judgments changed significantly as a function of both the actual TTA (p < 0.0001) and sensory condition (p < 0.0001). Although no main effect for gender was found (p = 0.19), the way the TTA judgments varied within each sensory condition for each gender was different (p < 0.0001). Females tended to be as accurate under either condition (p ≥ 0.01), with the exception of TTA judgments made when the actual TTA was 2 seconds or less and 8 seconds or longer, during which the vision-and-hearing condition was more accurate (p ≤ 0.002). Males made more accurate TTA judgments under the hearing only condition for actual TTA values 5 seconds or less (p < 0.0001), after which there were no significant differences between the two conditions (p ≥ 0.01). Our data suggest that males and females use visual and auditory information differently when making TTA judgments. Although the sensory condition did not affect the females' accuracy in judgments, males initially tended to be more accurate when using their hearing only.

Vision science in sport update

The vision management of athletes is a pyramidal structure based upon two initial stages of screening for visual and ocular defects and correcting any refractive or binocular anomalies detected. These two stages, which are essential starting points, in fact constitute the application of habitual vision care to athletes. Truly specialised sports vision, which begins when these two initial stages are completed, is a relatively new field of activity for eye care practitioners. It requires the use of specialised instrumentation, the development of novel training methodologies and must be fully integrated in the training programme of elite athletes, hence requiring a close collaboration with the coaching staff.

A randomized clinical trial to evaluate ready-made spectacles in an adult population in India

Ready-made spectacles (RMS) have advantages; however, visual performance and satisfaction has not been evaluated. A 1-month, double-masked, randomized clinical trial comparing planned continued use and visual performance of RMS to Custom Spectacles (CS) in adults aged 18-45 years with > or =1 diopter (D) of uncorrected refractive error (URE). A total of 373 of 400 participants (93%) completed; mean age was 30 +/- 9 years, and 58% were female. Average URE was 2.21 +/- 1.31D and habitual vision was 0.58 +/- 0.21 logMAR (logarithm of Minimum Angle of Resolution, 20/63(+1) Snellen acuity). Ten participants with habitual vision better than 20/40 were excluded (3%). A lower proportion in the RMS group intended to continue to wear the study spectacles after 1 month (165/183, 90% vs 174/180, 97%, P = 0.02). Spectacle vision in the eye with lower URE was 0.08 +/- 0.15 vs 0.02 +/- 0.08, P < 0.0001 and higher URE was 0.12 +/- 0.18 vs 0.02 +/- 0.08, P < 0.0001 (logMAR) for RMS and CS. Subgroup analyses excluding participants with astigmatism > or =2.00 D and anisometropia > or =1.00 D (74/363, 20%) found no difference in planned continued use (139/143, 97% vs 141/146, 97%, P = 1.0) for RMS vs CS. While vision is slightly better with CS, 90% of an adult population with URE planned to continue to use their RMS at 1 month. Furthermore, if those without high astigmatism or anisometropia are excluded, virtually all are satisfied with RMS and there is no difference when compared with CS. The findings of this study support the use of RMS for the delivery of refractive services in settings where there is a high level of need, limited resources and low access to refractive services.

Impact of Cataract Screening Outreach in Rural China

To examine differences between patients with cataract detected during screening and presenting to clinic in rural China. Subjects were recruited from 27 screenings and an eye clinic in the same town. All had pinhole-corrected vision < or =6/18 in > or =1 eye due to ophthalmologist-diagnosed cataract. Subjects were administered a previously validated questionnaire on barriers to surgery in four areas: knowledge (K), perceptions of quality (Q), transportation (T), and cost (C). Screening group (SG; n = 120) and clinic group (CG; n = 120) participants did not differ from eligible, examined screening and clinic patients respectively in age, gender, or vision. SG participants were significantly more likely to be female (P = 0.002) and had a smaller housing area and less education (P < 0.001 for both) than those in the CG. Those in the CG were more likely to be blind (habitual VA < or = 6/60) in the better-seeing eye (P = 0.05) and more willing to undergo and pay for cataract surgery (P < 0.001 for both) than SG. In logistic regression models, SG subjects had significantly lower quality scores (P < 0.001) and better habitual vision (P = 0.02) than did CG participants, and SG subjects who agreed to cataract surgery (78.3%) had significantly higher knowledge scores (P < 0.001) than those who refused. Screening outreach has the potential to ameliorate disparities in access to cataract surgery in rural China, as it appears more likely to detect patients with cataract with gender-related, economic, educational, and attitudinal barriers to surgery. However, education may be needed to convince screening subjects to undergo surgery.