Vision Tests (vision + test)

Distribution by Scientific Domains

Kinds of Vision Tests

  • colour vision test


  • Selected Abstracts


    Optimal reading speed in simulated cataract: development of a potential vision test

    OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 4 2001
    Bhavesh Patel
    Summary Previous studies suggest that optimal reading speed is unaffected by cataract, yet is significantly reduced in age-related macular disease. This raises the question of whether a reading speed test could be developed to assess potential vision after cataract surgery. In this study, 20 young subjects, with and without a simulation of dense cataract, read aloud Bailey-Lovie word charts. From the results, critical print size, optimal reading speed and word acuity were calculated. The simulated cataract reduced word acuity and increased the critical print size, yet optimal reading speed remained unchanged. Measurements were also taken with the charts in reversed contrast polarity. Reversing the contrast polarity of the charts improved the word acuity and optimal reading speed with the cataract simulation. The results suggest that optimal reading speed could be used as a potential vision test. Further investigations using patients with cataract and ARMD are required. [source]


    The ChromaGen contact lens system: colour vision test results and subjective responses

    OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 3 2001
    Helen A. Swarbrick
    Summary The ChromaGen lens system is designed to enhance colour perception in colour vision deficiency (CVD). To investigate its efficacy, 14 CVD subjects were prescribed ChromaGen contact lenses. Colour vision tests (Ishihara, Farnsworth Munsell D-15, Farnsworth Lantern) were administered at baseline, lens dispensing, and after a 2-week lens-wearing trial during which subjective responses were recorded daily using visual analogue scales. ChromaGen lenses significantly reduced Ishihara error rates(p<0.001; ANOVA), particularly for deutan subjects. There was also a significant reduction in errors(p<0.005) on the D-15 test. Conversely, lens wear had no significant effect on Farnsworth Lantern test performance. Subjectively, subjects reported enhanced colour perception, but poor vision in dim light. Judgement of distance and motion were only slightly affected. We conclude that ChromaGen lenses may enhance subjective colour experience and assist in certain colour-related tasks, but are not indicated as an aid for CVD in occupations with colour vision-related restrictions. [source]


    Which color vision test should be used in progressive cone dystrophy?

    ACTA OPHTHALMOLOGICA, Issue 2007
    AAHJ THIADENS
    Purpose: The early manifestation of progressive cone dystrophy (COD) can remain unrecognized due to the relatively normal macular appearance. Color vision testing can be very useful as a first diagnostic step. The many available color vision tests have different benefits and shortcomings. We aimed to identify which test would be preferred to use in a clinical setting as a first step towards diagnosis of COD. Methods: We compared patients (n=18) derived from the ophthalmogenetic unit of Erasmus Medical Center and University Medical Center Nijmegen, with various levels of cone dysfunction. Golden Standard for diagnosis of COD was a diminished photopic ERG and a relative central scotoma on Goldmann perimetry. Controls (n=33) were patients from these clinics with other diagnoses or healthy companions of COD patients. We estimated sensitivity and specificity of the Ishihara test, Lanthony Desaturated and Saturated Panel D15 test, the Hardy-Rand-Rittler (HRR) pseudo-isochromatic plates, and the Nagel anomaloscope. We analyzed sensitivity, specificity and the predictive value with receiver operating characteristic curve (ROC). Results: The HRR test had the highest sensitivity and specificity for protan and deutan axes. HRR and Ishihara had the highest predictive value. Lanthony Panel D15 test did not have an additional predictive value for severe color vision defects. The Nagel anomaloscope was not reliable due to low specificity. Its results showed high variations among both healthy and afflicted individuals. Conclusions: The HRR test was the most useful for COD. This test had the highest sensitivity in detecting early dysfunction of all three cone types, and it adequately quantifies the level of cone dysfunction in the course of the disease. [source]


    One of Australia's greatest cricketers was a protanope: a genetic detective story solved with the help of Schmidt's sign

    CLINICAL AND EXPERIMENTAL OPTOMETRY, Issue 6 2005
    Ross W. Harris BAppSc LOSc FVCO
    Abnormal colour vision is under-represented among first class cricketers (Goddard N and Coull B BMJ 1994; 309: 16841685) and interviews with cricketers, all of whom had a mild colour vision defect, suggest there may be times when they lose sight of the red cricket ball against green surrounds (Hams and Cole Clin Exp Optom 2005; 88: 176,180). It is possible that severe abnormal colour vision precludes playing cricket at its highest competitive level. It is known that Bill Ponsford, who played Test cricket from 1924 to 1934 and was one of Australia's greatest batsmen, had abnormal colour vision. We have diagnosed him to be a protanope by tracing the abnormal colour vision exhibited by some of his descendents. We used Schmidt's sign using the Medmont ClOO colour vision test to identify carriers of the protan gene to trace the protanopic gene to Ponsford with greater certainty. That such an accomplished batsman and highly regarded outfielder should have a severe colour vision deficiency suggests that abnormal colour vision might not be, or at least need not be, a handicap to playing cricket at the most competitive levels. [source]


    State motor vehicle laws and older drivers

    HEALTH ECONOMICS, Issue 4 2005
    Michael A. Morrisey
    Abstract After teenage males, elderly individuals have the highest per capita motor vehicle fatality rate in the United States. Surprisingly, there has been only limited work examining the effect of state motor vehicle laws on older driver fatalities. This paper uses state-level data from the 1985,2000 Fatality Analysis Reporting System to examine the effects of changes in state laws dealing with license renewal, seatbelt use, speed limits, and driving while intoxicated on fatalities among drivers and others aged 65 and over. Negative binomial regressions are estimated using alternatively state and year fixed effects, or age and year fixed effects. In-person license renewal reduced fatalities among the oldest drivers, but vision tests, road tests and the length of the license renewal cycle generally did not. In terms of policies that apply to all drivers, seatbelt laws, particularly with primary enforcement, were generally the only policies that reduced older driver fatalities. These results are noteworthy because a number of policies that have been effective towards increasing younger driver safety are not relevant for older drivers, implying that policymakers must think broadly about using state laws to improve older driver safety. Copyright © 2004 John Wiley & Sons, Ltd. [source]


    Occupational colour vision requirements for police officers

    OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 6 2008
    Jennifer Birch
    Abstract Inclusion of public service professions in the UK Disability Discrimination Act in 2004 prompted a review of occupational colour vision requirements for police officers. Changes in the regulations which existed prior to 2003 were proposed. The aim of this study was to obtain the views of serving police officers in Northern Ireland on the importance of good colour discrimination in everyday police work and on the recruitment regulations for patrol constables introduced in 2003 in mainland UK. These views were obtained by means of a questionnaire and informal discussions. More than 65% of police officers who responded to the questionnaire considered that good colour vision was very important for effective policing. Fewer than 2% considered that colour vision was unimportant. Experienced police officers agreed that the employment of colour-deficient patrol constables, as permitted in the new regulations, would lead to reduced efficiency and organisational difficulties at the local level. A number of everyday activities were described which showed the need for accurate colour discrimination. The change in recruitment policy and the lack of clarity in the new regulations show inadequate appreciation of the needs of the occupation, of different types of colour vision anomalies and of the diagnostic function of colour vision tests. Failure to provide guidance on appropriate colour vision tests, examination procedures and counselling services is likely to result in inconsistent employment policies in different police forces. It is recommended that the colour vision standard in place prior to 2003 is reinstated at the recruitment stage. The Ishihara test should be used for screening, and colour-deficient applicants further examined with the Farnsworth D15 test as a replacement for the City University Test 2nd edition. [source]


    Pulfrich's phenonenon in a case of optic nerve hypoplasia

    OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 1 2008
    Gordon Heron
    Introduction:, Optic nerve hypoplasia (ONH) is a congenital deficiency of retinal ganglion cells and their axons that form the optic nerve. This condition is associated with visual deficits ranging from no light perception in severe cases to vision within normal ranges in mild cases of ONH. In mild cases, deficits can be limited to sectoral anomalies in the visual field and normal vision with colour vision anomalies have been reported. We report here a case of mild ONH with visual symptoms relating to Pulfrich phenomenon (PP) occurring spontaneously. Methods:, A 12 year girl presented with typical visual symptoms (bumping into objects when walking, poor object location at tennis) associated with the spontaneous PP. A simple pendulum revealed a perceived anticlockwise ellipse indicative of a left eye defect. This was neutralised by an 85% transmission filter placed before the right eye. The inter-ocular latency difference was calculated to be 0.88 (S.D., 0.55) ms. Results:, Fundus biometry showed an asymmetry in optic nerve size, the left being smaller than the right. Visual fields, anomaloscope and other colour vision tests, and both flash and pattern-reversal stimuli Visually Evoked Potentials showed no difference in visual function between the right and left eyes. Conclusions:, A case of very mild ONH gives inter-ocular normal vision and visual function and yet a subtle inter-ocular delay occurs resulting in visual symptoms associated with PP. These were completely removed with tinted spectacles. [source]


    Vision screening of older people

    OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 6 2007
    Zahra Jessa
    Abstract A recent systematic review found that between 20% and 50% of older people in the UK have undetected reduced vision and in most cases this is caused by refractive error or cataracts, and is correctable. Two approaches to improve the detection of these problems are to better publicise optometric services and to carry out community-based vision screening of older people. Screening programmes should pass the Wilson criteria and a consideration of these highlights three inter-related questions: ,Is vision screening effective at detecting correctable low vision in older people?'; ,Which tests should be included?' and ,Which venues are most appropriate?' We carried out a systematic review to investigate these questions. For the first question, only one study was found which met our selection criteria. The ,gold standard' eye examination in this study lacked several important components, and the vision screening method that was used was not found to be very effective. The review revealed other studies, which, although not meeting our selection criteria, included relevant information. The screening studies highlight the lack of agreement on the content of a gold standard eye examination and of the test(s) that should be used to screen vision. Visual function in older people is not adequately described by high contrast visual acuity (VA), nor by self-reports of visual difficulties. Other tests that may be relevant include visual field testing, low contrast VA, contrast sensitivity and stereo-acuity. The pinhole test has often been used in attempts to detect uncorrected refractive errors, but results from this test can be problematic and possible reasons for this are discussed. Appropriate venues for vision screening are contingent upon the format of the vision screening programme. There is still uncertainty over the battery of vision tests that are most appropriate. This, and optimum venues for screening, require further research before it can be fully determined whether vision screening of older people meets the Wilson criteria. If a vision screening programme using a battery of vision tests, perhaps computerised, can be established, then this should be tested to determine the sensitivity and specificity for detecting the target conditions. Ultimately, longitudinal studies are necessary to determine whether such a screening programme will lead to improved visual performance and quality of life in older people. [source]


    Technical Note: The effect of refractive blur on colour vision evaluated using the Cambridge Colour Test, the Ishihara Pseudoisochromatic Plates and the Farnsworth Munsell 100 Hue Test

    OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 3 2007
    Sri Thyagarajan
    Abstract The results of a prospective study examining the effect of refractive blur on colour vision performance in normal subjects measured with three different colour vision tests are reported. The Farnsworth Munsell 100 Hue (FM100) and Cambridge Colour Test (CCT) results were significantly affected at +6 D of spherical refractive blur, whereas those from the Ishihara Pseudoisochromatic Plate (IPP) test were not. In a clinical setting, correction of refractive error up to 3 D for colour vision testing with these tests may not be required. Poor colour vision should not be attributed solely to refractive causes of poor visual acuity (Snellen equivalent: >6/36). Fastest test times were achieved using IPP, followed by CCT. [source]


    The ChromaGen contact lens system: colour vision test results and subjective responses

    OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 3 2001
    Helen A. Swarbrick
    Summary The ChromaGen lens system is designed to enhance colour perception in colour vision deficiency (CVD). To investigate its efficacy, 14 CVD subjects were prescribed ChromaGen contact lenses. Colour vision tests (Ishihara, Farnsworth Munsell D-15, Farnsworth Lantern) were administered at baseline, lens dispensing, and after a 2-week lens-wearing trial during which subjective responses were recorded daily using visual analogue scales. ChromaGen lenses significantly reduced Ishihara error rates(p<0.001; ANOVA), particularly for deutan subjects. There was also a significant reduction in errors(p<0.005) on the D-15 test. Conversely, lens wear had no significant effect on Farnsworth Lantern test performance. Subjectively, subjects reported enhanced colour perception, but poor vision in dim light. Judgement of distance and motion were only slightly affected. We conclude that ChromaGen lenses may enhance subjective colour experience and assist in certain colour-related tasks, but are not indicated as an aid for CVD in occupations with colour vision-related restrictions. [source]


    Visual function of police officers who have undergone refractive surgery

    AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 11 2006
    Jeffery K. Hovis OD
    Abstract Introduction The visual acuity and contrast sensitivity of police recruits and officers was evaluated in both normal and dim illumination conditions to determine whether officers who have had refractive surgery have compromised night vision. Methods The control group consisted of 76 officers and recruits who have not had refractive surgery and the refractive surgery group consisted of 22 officers and recruits who had refractive surgery. Visual acuity and contrast sensitivity were measured under both room illumination and dim illumination. The room illumination test series included high contrast acuity, low contrast acuity and Pelli-Robson contrast sensitivity. The dim illumination test series included high contrast acuity, low contrast acuity, Pelli-Robson contrast sensitivity, license plate number acuity (with and without glare) and the Mesotest. Results The general findings were that the refractive surgery group had lower acuity scores on low contrast targets in both room and dim light levels along with a reduction in the Mesotest scores with a glare source compared to the control group. Conclusions Although refractive surgery police recruits and officers had reduced performance on some vision tests, these reductions were small and it is unlikely that their performance on vision related tasks would be compromised, on average. The major concern is the small number of refractive surgery candidates whose results were well outside the range of the non-surgical candidates. Their vision may be unacceptable for policing. Am. J. Ind. Med. 49:885,894, 2006. © 2006 Wiley-Liss, Inc. [source]


    Assessment of inherited colour vision defects in clinical practice

    CLINICAL AND EXPERIMENTAL OPTOMETRY, Issue 3 2007
    Barry L Cole PhD MAppSc BSc LOSc
    Background:, Colour vision deficiency (CVD) has a high prevalence and is often a handicap in everyday life. Those who have CVD will be better able to adapt and make more informed career choices, if they know about their deficiency. The fact that from 20 to 30 per cent of adults with abnormal colour vision do not know they have CVD suggests that colour vision is not tested as often as it should be. This may be because of practitioner uncertainty about which tests to use, how to interpret them and the advice that should be given to patients on the basis of the results. The purpose of this paper is to recommend tests for primary care assessment of colour vision and provide guidance on the advice that can be given to patients with CVD. Methods:, The literature on colour vision tests and the relationship between the results of the tests and performance at practical colour tasks was reviewed. Results:, The colour vision tests that are most suitable for primary care clinical practice are the Ishihara test, the Richmond HRR 4th edition 2002 test, the Medmont C-100 test and the Farnsworth D15 test. These tests are quick to administer, give clear results and are easy to interpret. Tables are provided summarising how these tests should be interpreted, the advice that can be given to CVD patients on basis of the test results, and the occupations in which CVD is a handicap. Conclusion:, Optometrists should test the colour vision of all new patients with the Ishihara and Richmond HRR (2002) tests. Those shown to have CVD should be assessed with the Medmont C-100 test and the Farnsworth D15 test and given appropriate advice based on the test results. [source]