Effect of Illumination on Colour Vision Testing with Farnsworth-Munsell 100 Hue Test: Customized Colour Vision Booth versus Room Illumination

PURPOSE: To evaluate a customized, portable Farnsworth-Munsell 100 (FM 100) hue viewing booth for compliance with colour vision testing standards and to compare it with room illumination in subjects with normal colour vision (trichromats), subjects with acquired colour vision defects (secondary to diabetes mellitus), and subjects with congenital colour vision defects (dichromats). METHODS: Discrete wavelengths of the tube in the customized booth were measured using a spectrometer using the normal incident method and were compared with the spectral distribution of sunlight. Forty-eight subjects were recruited for the study and were divided into 3 groups: Group 1, Normal Trichromats (30 eyes); Group 2, Congenital Colour Vision Defects (16 eyes); and Group 3, Diabetes Mellitus (20 eyes). The FM 100 hue test performance was compared using two illumination conditions, booth illumination and room illumination. RESULTS: Total error scores of the classical method in Group 2 as mean+/-SD for room and booth illumination was 243.05+/-85.96 and 149.85+/-54.50 respectively (p=0.0001). Group 2 demonstrated lesser correlation (r=0.50, 0.55), lesser reliability (Cronbach's alpha, 0.625, 0.662) and greater variability (Bland & Altman value, 10.5) in total error scores for the classical method and the moment of inertia method between the two illumination conditions when compared to the other two groups. CONCLUSIONS: The customized booth demonstrated illumination meeting CIE standards. The total error scores were overestimated by the classical and moment of inertia methods in all groups for room illumination compared with booth illumination, however overestimation was more significant in the diabetes group.

Computer adapted Ishihara test in 104 students / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the validity of computer-adapted Ishihara test and the concordance with classic Ishihara test for the diagnosis of colour blindness. The sensitivity and the specificity of computer-adapted Ishihara test and potential usefulness of the test for detecting congenital colour blindness or colour vision deficiency were discussed.METHODS: Colour vision of 104 university students aged between 20 and 23 (median 21) years was evaluated by two methods. These methods are: 1) Individual test method based on computer-adapted Ishihara colour plates; 2) Individual test method based on classic method of exposing Ishihara colour printed plates. The capabilities of students perceiving colours were evaluated by these two different methods. The specificity, concordance and validity for the computer adapted Ishihara test method were investigated.RESULTS: There were 6 male and 1 female colour blind students. The pedigree of the female student proved to have a carrier mother and colour blind father. The incidence of colour blindness was 13.6 % (6/44) among males and 1.7%(1/60) for females. The incidence of colour blindness in whole population was 6.7 % (7/104). These students had not been aware that they have colour vision deficiency before our examination tests. Test results of students with normal colour vision and the students with colour blindness were compared as well as the two test methods in terms of concordance. The sensitivity and the specificity were both found to be 100 %and concordance was also found 100 %.CONCLUSION: Computer-adapted Ishihara test is digitally mastered, and remains true with respect to the basic concepts of color vision testing. It has obvious advantages over manual testing because its total test time and its error scores are standardized. It has been found 100% in agreement with the golden standard of classic Ishihara test. These features make this test original and dependable one.

A Computerized Scoring Method of The Hahn Double 15 Hue Test / 예방의학회지

The Hahn double 15 hue test is used for social and vacational aptitude test to separate strongly and mildly affected subjects among the colour vision defective persons, detected using colour vision test. However, the assessment of colour vision defect type and severity is based on the hue confusions which are represented diagrammatically on Hahn double 15 hue score sheet, this qualitative assessment of the test results have not provide a numerical score suitable for mathematical analysis. This paper presented a new proposal for quantitatively scoring the Hahn double 15 hue test based on those hue confusions made by the subject. With this program large numbers of double 15 hue test results can be processed easily and rapidly, and program helps to compare the severity of specific type colour vision defect and monitor acquired colour vision defect which has various disease process, continuously.

Evaluation of congenital colour vision deficiencies

Three hundred patients who have congenital colour vision deficiencies were examined at the author's eye clinic for 3 years (1987-1990) using 5 types of colour vision tests: Hahn's, TMC's, Okuma's (new), H-R-R's colour vision tests and Double 15 Hue Test (Hahn). The results obtained from each test were quite different in type and grade, and the summarized results were considered to be the best: Type: protan 23.3%, deutan 76.0%, unclassified 0.7% Grade: mild 20.3%, medium 25.3%, strong 54.4% The frequency of coincidence both in type and grade between the summarized results and those of each test were compared, and the highest was 62.3% in Double 15 Hue Test. The efficiency of the author's colour vision test and Double 15 Hue Test were evaluated with the data in this clinical trial, and they were found to be useful for classifying the type and estimating the grade of the congenital and also acquired colour vision deficiencies.