Evaluation of the performance of the Waggoner computerised colour vision test

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.

Dear Sir, As members of the state's medical board, the authors wish to share some of the difficulties encountered while testing candidates for color vision deficiency (CVD). Though many methods for color vision testing are available, there is no consensus on the ideal method, with different countries using different tests. In India, the Ishihara charts are the most widely used, with additional use of Edridge-Green lantern in civil services and Martin lantern in armed forces.[1,2] The Ishihara test is quick and easy and is an excellent screening tool to detect those with red-green CVD. However, it has a limited ability to classify CVD and determine its severity. Organizations that require the correct recognition of colored signals (principally transport groups such as the Civil Aviation Authority, Railways, Maritime, and Naval and Air force) depend on a standard lantern test which imitates actual signal systems simulating the workplace. Lanterns do not specifically screen for color defects. It is surprising that even now, the general design of lanterns has not changed very much since their creation in 1891. With the exception of the Farnsworth lantern used in the USA, there are scarce studies on the validation and reliability of lanterns. The panel tests, including the Farnsworth Panel D-15 and Farnsworth–Munsell 100-hue tests, are much more accurate in classifying color deficiency. Farnsworth Panel D-15 Test is considerably quicker and more convenient test for routine clinical use. Though not very sensitive, its speed and accuracy make it useful. The relative insensitivity can also be an asset in judging the practical significance of mild degrees of color deficiency. For example, individuals who fail the Ishihara plates but pass the D-15 panel will probably not have color discrimination problems under most circumstances and in most jobs.[3] Nagels anomaloscopes is considered the gold standard for color vision testing in clinical research, however, it is an expensive instrument requiring an experienced examiner's skills. Color vision is graded into higher and lower grade depending on the size of the aperture in the Edridge-Green lantern (1.3 mm vs. 13 mm),[1] with the technical services category of Indian civil services, which includes police services requiring higher grade of color vision. The United States police service no longer implements a color vision standard though monochromats are barred.[4] Those who fail initial color vision screening by pseudoisochromatic plates should be further evaluated by anamaloscope or D-15 test to include anomalous trichromats who are the most numerous among the CVD persons. In an ongoing study, 500 candidates who appeared in the divisional medical board were studied. Ishihara chart was used for initial screening of all candidates with further use of Edridge-Green lantern for candidates found to have CVD and selected for jobs requiring high grade of color vision. Sixty candidates (13%) were found to have CVD; 39 of those were selected for jobs requiring accurate color perception. None of the candidates found to have CVD on testing by Ishihara chart could pass the lantern test. Only 21 candidates found to have CVD were previously aware of their deficiency. Since color judgment is an integral part of work in various occupations, a screening test to establish color vision should be undertaken while giving career's advice. An early diagnosis of CVD might allow for early modifications in educational and other activities. Furthermore, there is a need to supplement the existing color vision tests for various services in India, with more objective, diagnostic tests such as the D-15, maintaining standard illumination. Use of color enhancing appliances (X-chrome and chromagen contact lenses) should be ruled out. Computer-based programs are needed so that easily reproducible and acceptable methods of testing are developed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Effect of EnChroma glasses on color vision screening using Ishihara and Farnsworth D-15 color vision tests

Color vision research is not new for the Federal Aviation Administration (FAA); the Civil Aerospace Medical Institute has been conducting color vision research and publishing the results since 1967 ( 3 ). The FAA originally initiated color vision research because of the emerging use of color coding in the airport environment and the FAA has continued a line of color vision research because of the increasing use of color coding resulting from changing technology inside the cockpit, on air traffic control displays, and in the airport environment. Color can be used to convey meaning without supplemental signage such as the ubiquitous traffic signal that alerts drivers to proceed with caution via a yellow flashing light or to stop via a red flashing light. However, that meaning is only conveyed if the driver can distinguish between the yellow and the red colors. Approximately 8 to 10% of the male population ( 5 ) has a congenital color vision deficiency and, depending upon the type and severity of that deficiency, that task of interpreting the meaning of color coding may be difficult or impossible. Consequently, the FAA has long maintained a color vision standard for aero-medical screening to ensure that pilots and air traffic controllers can perform safety-related tasks without adverse consequences. Throughout the past few years, the FAA has explored a variety of color vision tests, searching for a valid screening test that has high sensitivity and specificity, meaning the ability to detect the presence or absence of the deficiency, respectively. Basically, color vision tests can be categorized as diagnostic, screening, or occupational tests. Diagnostic tests are designed to specifically diagnose the type and degree of deficiency, the screening tests focus on differentiating between normal or deficient color vision, and the occupational tests seek to separate those capable versus incapable of certain tasks such as identifying colors of wires or lights (e.g., the Farnsworth Lantern test that was developed to assess the ability of potential Navy signalmen for identifying red, green, and white lights). A few tests have been developed for the purpose of precisely diagnosing and classifying color vision; however, when color vision test scores are compared to performance on occupational tasks such as identifying or discriminating colors used in signal lights, precision approach path indicator (PAPI) lights, colored navigation lights, color coded map reading tasks, color coded air traffic control displays, and cockpit displays, a specific cut-point on those selection tests has not been found that can fully separate those who can from those who cannot accurately perform the color-coded pilot or air traffic control tasks. Some tests, including new computerized instruments, have been designed to differentiate defects involving the long wavelength sensitive cones (protan-type), middle wavelength sensitive cones (deutan-type), and short wavelength sensitive cones (tritan-type). Congenital protan and deutan deficiencies are, collectively, extremely common, affecting 1 in 12 men and 1 in 230 women; however, recent evidence indicates that tritan defects are virtually never present at birth (e.g., congenital) and the inherited forms involve S cone photoreceptor degeneration that develops later in life with the exact onset depending upon the specific mutation ( 1, 4 ). Thus, the exact frequency of inherited tritan defects is uncertain; however, it is probably less than 1 in 500. In part, because the underlying pathophysiology has not been well understood, few tests have been available that are capable of detecting tritan deficiencies. In the past, those tests included the single Farnsworth F2 pseudoisochromatic plate (PIP), the Moreland anomaloscope, the Hardy, Rand, Rittler PIP test, and, most recently, the Oculus anomaloscope. Consequently, the occupational color vision tests used by most agencies only screen for the most common (protan and deutan) types of defects. The newly developed computerized color vision tests, including the Colour Assessment and Diagnostic Test, the Cambridge Colour Test, the Cone Contrast Test, and the Computerized Color Vision Test, are all designed to detect tritan defects. However, tritan weaknesses have been noted in several of the FAA ‘ s recent studies in much higher than the traditionally expected numbers and diagnostic agreement is low among those tests when tritan deficiencies are involved. In the past, the FAA and other regulatory organizations have not, or have rarely, required tritan color vision screening in their occupational screening because of the following three factors: the rarity of the congenital defect, the unknown number of individuals affected by acquired deficiencies, and the lack of effective, reliable, valid, and affordable equipment with which to diagnose the deficiency.

Background: Pseudoisochromatic color vision tests are commonly used to screen for color vision deficiency (CVD). Although most color vision normal (CVN) individuals read all plates correctly, a remarkable proportion have errors. Objective: This study aimed to determine the typical and atypical error responses to the Ishihara and Waggoner PIP24 (W-PIP24) tests of CVN and CVD individuals. Methods: This study recruited 59 CVN and 63 congenital red-green CVD individuals. Participants were tested with the Ishihara and W-PIP24 tests. The participants’ responses were recorded, and typical and atypical errors were determined. Results: The rate of atypical errors in the CVN group was 21% in the Ishihara test and 9% in the W-PIP24 test, while those in the CVD group were 100% and 60%, respectively. The CVN and CVD groups tended to have more atypical errors on the Ishihara test than on the W-PIP24 test. Moreover, CVD individuals tended to have more atypical errors in the transformation plates in both tests. Conclusion: CVN individuals may misread the plates in the Ishihara and W-PIP24 tests for reasons other than the normality of color vision; therefore, counting only typical errors may eliminate the chance of CVN individuals misreading the number on the plates. The most significant finding of this study was that clinicians should perhaps only consider typical errors as “errors” on both tests.

A remarkable, and often underappreciated, property of the human visual system is its ability to perceive and distinguish colour. This occurs through a myriad of physiological and neurological processes with disruptions anywhere along the visual pathway having the potential to affect colour perception. This ability to perceive and process colour coded information, and human colour vision more generally, are valuable components of vision which, in addition to encoding information about our environment, provide clinicians with insights into the functioning of the retina and neural visual pathways. In clinics, monitoring occurs through tests that assess the ability to see, distinguish, and make use of colour.The primary purpose of colour vision assessment often varies in hospital clinics compared to community practice. In a hospital setting, the colour vision deficiencies of primary interest will be acquired in nature. The detection, classification, quantification, and measurement of such deficiencies can enable early‐stage detection of retinal disease and an additional measure for monitoring progressive conditions.Within community practice, the primary interest often will be congenital colour vision deficiency. Congenital defects are present in ~8% of males and ~0.5% of females and affect education and occupational suitability. The early detection of such deficiencies is important to identify any potential colour vision deficiency that may impact a child's education, or an adult's occupational suitability. Ensuring children are not educationally disadvantaged due to an inherited colour vision deficiency, whilst also ensuring that individuals employed in occupational roles that require a certain level of chromatic sensitivity are able to do so safely is hugely important and a key role of optometric practitioners working in the community.Although most colour vision deficiencies encountered in community practices will be congenital, patients will also be encountered with acquired defects from ocular or neurological pathologies. In these cases, colour vision testing may play a key role in diagnosis of pathology.There is a discrepancy between the quality of tools available in specialist centres and community and hospital clinics. Many of the insights gleamed from work carried out in specialised colour assessment clinics are currently not fully utilised within community practice. During this session we will review the main clinical colour vision tests, highlighting the differences between the tests that are most useful for diagnosing congenital and acquired defects.This presentation will provide a timely refresher on colour vision testing, its importance, and, critically, the limitations present in several colour vision tests in current use. This presentation is likely to be of interest to those who regularly assess colour vision, and even more important for those who do not often use colour vision tests and who may therefore benefit from adopting this additional clinical tool.

Efficacy of red contact lens in improving color vision test performance based on Ishihara, Farnsworth D15, and Martin Lantern Test

: All clinical color vision tests currently used in the medical examination of pilots were studied regarding validity for prediction of performance on practical tests of ability to discriminate the aviation signal colors, red, green, and white given under both day and night conditions. Those same practical tests are given to pilots with color vision deficiency who apply for a waiver of the Class II or Class III color vision standards. Subjects with varying type and degree of color vision deficiency (n=122) and subjects with normal color vision (n=120) were classified with the anomaloscope and given both practical and clinical tests. The clinical color vision tests included the American Optical Company plates (1965 and 1940 Editions), AOCHRR plates (2nd Edition), Ishihara plates (14-, 16-, 24-, and 38-plate tests), Dvorine plates, Richmond plates, Farnsworth Lantern, School of Aviation Medicine Color Threshold Tester, Titmus Tester, Titmus II Tester, OPTEC 2000 Tester, and Keystone Orthoscope/Telebinocular test. The criterion tests required naming the colors of actual signals produced by the Aviation Signal Light, with the same test procedures and viewing distances used in actual practical tests. The Farnsworth Lantern and several plate tests were the best clinical tests for predicting ability to identify the colors of aviation signals. Individuals with color vision deficiency identified signal colors better at night than during the day. Recommendations for improving the disposition criteria of some clinical tests, and for discontinuing several obsolete tests are discussed. Aviation signal lights, Color vision screening, Color vision deficiency

Clinical color vision evaluation has been based primarily on the same set of tests for the past several decades. Recently, computer-based color vision tests have been devised, and these have several advantages but are still not widely used. In this study, we evaluated the Waggoner Computerized Color Vision Test (CCVT), which was developed for widespread use with common computer systems. A sample of subjects with (n = 59) and without (n = 361) color vision deficiency (CVD) were tested on the CCVT, the anomaloscope, the Richmond HRR (Hardy-Rand-Rittler) (4th edition), and the Ishihara test. The CCVT was administered in two ways: (1) on a computer monitor using its default settings and (2) on one standardized to a correlated color temperature (CCT) of 6500 K. Twenty-four subjects with CVD performed the CCVT both ways. Sensitivity, specificity, and correct classification rates were determined. The screening performance of the CCVT was good (95% sensitivity, 100% specificity). The CCVT classified subjects as deutan or protan in agreement with anomaloscopy 89% of the time. It generally classified subjects as having a more severe defect compared with other tests. Results from 18 of the 24 subjects with CVD tested under both default and calibrated CCT conditions were the same, whereas the results from 6 subjects had better agreement with other test results when the CCT was set. The Waggoner CCVT is an adequate color vision screening test with several advantages and appears to provide a fairly accurate diagnosis of deficiency type. Used in conjunction with other color vision tests, it may be a useful addition to a color vision test battery.

Five thousand one hundred and twenty-nine Wis- consin children, ages 4 -12 years, were tested for color- vision deficiencies using a newly devised, precisely cali- brated paper-and-pencil test. The disposable 1-page test consisted of 1 demonstration and 8 test panels. Thousands of copies of the test were produced, and they were distrib- uted and administered in classrooms by teachers. Children wrote directly on the test and were allowed to trace over the symbols with a pencil or crayon, if they had difficulty. Performance on the paper-and-pencil color vision test was compared with that on conventional tests of color vision including Ishihara's tests, the American Optical-Hardy Rand and Rittler (AO-HRR) plate test, and the APT-5 Color Vision Tester. Older children were also tested on the Nagel Anomaloscope. All the children who were classified as having a color vision deficiency by the paper-and-pencil test also failed one or more of the conventional tests. Likewise, among children who passed the paper-and-pencil test, none were classified as having a color-vision defect from the results on the conventional tests. In the sample of all males, 7.5% were classified as having a color-vision deficiency, which is consistent with what has been observed previously in large population studies. Children who were classified as having color vision deficiencies were examined further us- ing a new minimalist genetic test that was shown to be accurate and reliable. Genetic material derived from buccal swabs was used to determine the type of deficiency, protan vs. deutan, and to provide added information about severity. Among the subjects for whom type could be determined, 27% were protans, consistent with large population studies in which approximately 25% of red-green deficiencies have been found to be of the protan type. Classification of the severity of the deficiencies determined from the paper-and- pencil test plus minimal genetics were in good agreement with classification based on a battery of conventional tests. In conclusion, we found the methods used here to be rapid, efficient, and reliable for testing color vision in children.

Comparison of two screening procedures for testing colour perception: Ishihara plates vs. digital replication Purpose: The study was designed to prove that the digitalized colour vision test integrated into the Optovist II is equivalent to the traditional Ishihara colour charts. Methods: Colour vision was tested with a sample size of 220 subjects (36 colour-deficient) and three different test methods. A new version of the Ishihara tablets was used under standard lighting conditions and at a distance of about 75 cm. The colour vision test (digitalized Ishihara plates) of a calibrated Optovist II (Vistec AG, Olching) and an HMC anomaloscope (Oculus Optikgeräte GmbH, Wetzlar) were also used. The first 17 plates of the Ishihara test were assessed in both the Ishihara colour vision test and the Optovist II, because the plates contain 18–24 lines that are not suitable for testing in the vision-testing device. Results: The test subject was classified as colour-deficient after two false readings of the pseudoisochromatic plates. The Ishihara plates provided the correct result in 200 subjects compared to the gold standard anomaloscope. In contrast, the Optovist II rated correctly in a total of 202 subjects. In the case of the Ishihara plates, 17 persons with normal colour vision were identified as having a colour deficiency, and three colour-deficient persons were classified as colour-competent. The Optovist II classified 16 colourcompetent persons as colour-deficient, and two colour-deficient persons as colour-competent. In addition, it was possible to test for equivalence using the McNemar test and to verify this. Conclusion: The two test methods should be considered equivalent. Both methods – Ishihara plates and their digital replica in the Optovist II – should be used exclusively as a screening method. A test with the anomaloscope should be performed for the final diagnosis. Keywords: Ishihara colour vision test – pseudoisochromatic panels – color vision – anomaloscope – digital colour vision test

This network meta-analysis (NMA) was done to compare the performance of color vision tests in the detection of individuals with color vision deficiency (CVD). Medline (via PubMed), Embase, and Web of Science were comprehensively searched from inception of the databases to 17 January, 2023. Conventional meta-analysis of diagnostic indicators was performed. The superiority of a diagnostic approach was depicted using the Superiority (S) Index. Six studies were enrolled. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the curve of summary receiver operating characteristic of the Ishihara tests were 0.89 (0.81, 0.94), 0.99 (0.96, 1.00), 110.8 (18.1, 677.0), 0.10 (0.05, 0.20), 1105 (112, 10,930), and 0.98 (0.96, 0.99). Waggoner Computerized Color Vision Test ranked the best performance in the detection of CVD, followed by CAD test, Ishihara test, Fletcher Lantern test, and HHR test as the rest second to the fifth most effective modalities. This NMA revealed that CAD test, Ishihara test, Fletcher Lantern test, and HHR test had favorable diagnostic validity in the detection of CVD.

Evaluation of the Third edition of the City University Colour Vision Test.

A number of test methods have been developed to detect colour vision deficiency. The most commonly used colour vision tests (Ishihara test, Velhagen test) are simple and quick to detect anomalous colour vision, but most of them do not provide information on the type and severity of colour vision deficiency. The most accurate diagnosis can be achieved by anomaloscope. With this instrument, a numerical result expressing the type and severity of the colour vision deficiency can be obtained. The anomaloscope is a rather expensive instrument ($18,000), available only in a few ophthalmology practices, and the examination is tedious and requires competent staff. The aim of this study is to evaluate the results of a simple, rapid colour vision test using the proposed fuzzy inference system, which is suitable to replace the rather expensive anomaloscopy examination.

Purpose The aim of this study was to determine the prevalence and types of color vision deficiency (CVD) among primary school students in Alexandria, Egypt. Setting This study was carried out at three primary schools in Alexandria, Egypt. Patients and methods This cross-sectional study was carried out among three primary school students in Alexandria, Egypt. Ocular examination including visual acuity and color vision testing with Ishihara plates (38-plate edition) was performed for all the students included. Further assessment using the Farnsworth–Munsell 100-hue test was performed for students who failed the Ishihara plates test. Results A total of 1000 (495 males and 505 females) school students were screened for CVD. The mean age of the students was 9±2.16 years. The overall prevalence of CVD was 1.9%, with a prevalence of 2.8 and 0.9% in males and females, respectively, a statistically significant difference (P=0.04). Among the CVD students, 36.8% had deuteranopia, 31.5% had deuteranomaly, 26.3% had protanopia, and 5.3% had tritanopia. Conclusion The prevalence of CVD was 1.9%, with a male predominance, among primary school students in Alexandria. Deutan color vision defects were the most prevalent.