Guide to Eye Exams and Vision Screening

Screening and quantitative color blindness tests

During a comprehensive eye exam, you will always receive the Ishihara Color Vision Test for color blindness test, which is the most widely applied screening test invented by the Japanese ophthalmologist Shinobu Ishihara. The booklet of the test consists of typically 38 plates of many dots of various colors, brightness and sizes. Normal people can see clear numbers through these dots, which is beyond individuals with color blindness. Other abbreviated versions of this test comprise only 14 or 24 plates.

Reasons for color blindness

If you can not distinguish blue and yellow or red and green, or sometimes other people may correct the color you see, you probably have color blindness. Color blindness is neither a form of blindness nor a full range of color disability. People with color blindness usually lack the ability to see certain colors properly. This is just a form of vision deficiency.