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PubMedDate not supplied

[The examination of color vision using a 2 metameric equation method].

Modern anomaloscopes with four independent light channels (i.e. Besançon-Anomalometer which was presented in 1979 at the SFO Congress) allow accurate examinations of color vision. In our routine clinical examination, we use two metameric equations: the red-green Rayleigh equation and the blue-green Moreland equation. This so called Two-Equation-Method enables the diagnosis of congenital and acquired color vision defects in a precise qualitative as well as quantitative way. For both equations the goal of the examination is to measure the absolute matching range. Abnormal color vision is diagnosed if the absolute matching range is shifted and/or enlarged in one or both of the two metameric equations. In congenital colour vision deficiencies, the results are similar to those obtained with the Nagel anomaloscop. The different types of acquired defects are compared with the types of Verriest's classification. A computer controlled clinical examination of color vision, which will make the procedure simplier and shorter for the patient is actually being developed.

Color Perception↗
PubMed1989

[Theoretical patterns of the panel D-15 test in congenital dichromatic color vision defects].

In order to study the theoretical patterns of the panel D-15 test for congenital dichromatic color vision defects, the spectral reflectance for the 16 color caps of the panel D-15 test was measured with a spectro-photometer. Then, the chromaticity-coordinates of each color cap were calculated using the spectral distribution of standard illuminant C. The theoretical patterns of the panel D-15 test for dichromats were obtained based on the confusion lines. For this procedure, the slope of the line between the color cap and the convergence point on the CIE chromaticity diagram was obtained first. Then, the order of the arrangement was decided starting with the slope having the smallest cap number and continuing progressively. For the chromaticity coordinates of the convergence points the following values were used; x = 0.7465, y = 0.2535 for protanopia, x = 1.08, y = -0.08, x = 1.40, y = -0.40, and x = 1.70, y = -0.70 for deuteranopia, and x = 0.171, y = 0.000 for tritanopia. The results show a very clear similarity between the orientation axis obtained by simulation and the actual data. Therefore, it was confirmed that dichromats arrange the color caps in the order of the slope of the line between the color cap and the convergence point, when performing the panel D-15 test. Furthermore, it was suggested that the patterns of the panel D-15 test differ by the convergence points among dichromats even of the same type.

Color Perception↗
PubMed1989

[Theoretical patterns of the panel D-15 test in congenital red-green dichromats as a function of the chromaticity coordinate of the convergence points].

In order to determine whether or not the patterns of the panel D-15 test for congenital red-green dichromats change when the convergence point is changed, a simulation experiment was attempted assuming that dichromats arrange the color caps in the order of the slope of the line between the chromaticity coordinates of the color cap and the convergence point. For this procedure, chromaticity coordinates of the color cap were calculated using both the spectral distribution of standard illuminant C and the daylight fluorescent lamp (Toshiba-EDL). For this prediction, the chromaticity coordinates of the convergence points were changed according to y = 1-x. The results show several different patterns for both protanopia and deuteranopia under both illuminants. The range of the x chromaticity coordinates common to both illuminants was 0.6868 to 0.8552 when the protanopic patterns were obtained, while the range of the x chromaticity coordinates common to both illuminants for deuteranopic patterns was 1.0878 to infinity and minus infinity to -1.8153. As a result, it was suggested that the patterns of the panel D-15 test for red-green dichromats change according to the convergence points. Therefore, it was considered that this test cannot be used as a dependable measurement for color discrimination ability in cases showing dichromatic patterns.

Color Perception↗
PubMed1977

[A new sieve-test for testing colour vision (author's transl)].

From our results we can be sure that the colour test disk is at least as reliable for mass testing for colour blindness as the Ishihara isochromatic colour plates. In practice the test disk has the advantage of constancy of testing conditions and easy and quick procedure. If it is necessary to differentiate between protopia and deuteropia the colour test disk is significantly better Ishihara's colour plates.

Color Perception↗
PubMed1978

Further observations on the extramacular chromatic mechanisms.

Monochromatic targets presented at 30 degrees excentricity on orange, magenta and blue backgrouds are used. A small monochromatic light, 476 nm on orange, 551 nm on magenta and 621 nm on blue, is flashed at 3 cps-1 on the centre of the targets. The size of the targets is varied and their luminance adjusted using neutral filters until the flashing light is just not visible. This method allows the study of chromatic mechanism sensitivity and of retinal interactions (summation and inhibition). Some observations in normal as well as in pathological conditions are presented.

Adult↗
PubMed1977

The Mackenzie Memorial Lecture, 1977. Of divers colours.

I shall discuss the nature of the sensation of colour and the reason for our colour vision, leading on to the existence of defects in that sense. I will consider the different kinds of such defects and the arguments for the use of particular tests in varying circumstances. I report the result of a recent survey of the value of a careers advisory service for "colour blind" school children seen between 1965 and 1977 (primarily red-green blind). This leads to examples of the value of these tests in genetics, and in the early diagnosis of disease or toxicity. I shall also describe the various modifications I have made to the 100-hue test, with its eventual automation both for computation and recording. Finally, the recommendations I make for future progress cover routine examination, both on starting primary education and on entering secondary education, analysis of the colour task at work, and the adoption of an enlightened system of colour coding.

Adolescent↗