A variant to the Ishihara “pseudo- isochromatic” test (2005)

1 .
In 1917 , Professor Shibaru Ishihara ( 1879-1963 ) , a military doctor and future dean of the Imperial University of Tokyo , who had been a pupil of Stock in Jena, Axenfeld in Freiburg in Breisgau – and von Hess in Munich before being forced to return to his homeland following the outbreak of the First World War , developed a detection system of the daltonisme which is still practiced today , as remembered by all those who have made their “three days” for military service .
This test is made of several colored discs with different inks ( up to nine) , consisting of points of variable size and tone , which make indistinct , except for the color type , a certain sign that is hidden among this set. For example, a colorblind deutan will not easily distinguish a red sign on a predominantly green background .
The ” pseudo- isochromatic ” test called Ishihara – the full version consists of 38 tables – is particularly efficient (98% ) in the individuation of hereditary dyschromatopsias of protan and deutan kind .
Tables 1-25 present Arabic numerals . The numbers are signs whose reading is common to both Western and Eastern , and this is why – presumably – they were used in the international version of the test . Neither the letters of the Latin alphabet, or Chinese pictograms or Egyptian hieroglyphics would – in effect – was readable.
Tables that are 26 to 38 are designed for illiterate children : thery present sinuous traces: the examinee must follow them with a pencil or his own finger .

2 .
The series of works that I propose , modestly , is a cultural variant of the Ishihara test. It is applicable to both illiterate and literate people of any race or color : it is only necessary that the examiner and the examinee  agree on the names to be given to things.
To develop my humble suggestion , I adapted a test for visually impaired children , which is used today in the ophthalmological services of French hospitals : the optometric testing R. Rossano and J -B . Weiss- Inserm , which provides for the identification of some familiar icons of our childhood : car, pram, dog, chicken , flower, and so on.
And it is not without a hint of pride that I propose my test for color deficiency. As a painter and – of course – a specialist in perception , vision and – consequently – the color , I could not not speak with empathy to the 8% of the population that does not perceive – as it should be – the full range of the world around us, and I am confident that this simple synthesis Ishihara – Rossano -Weiss -Inserm -Puglia will help to better realize what they are missing.

(Google translation from French, redirected)


Ishihara test


Rossano-Weiss test