Ishihara Color Blindness Test

The Ishihara eye test is the most common clinical test administered by ophthalmologists when attempting to rule out the possibilities of color blindness in patients.

The test is made up of a series of simple colored plates with a multicolored design, made up entirely of differently colored dots arranged in a circle. Within the many dots is a series of differently colored dots that form a figure, or commonly, a number.

This test serves to single out individuals suffering from red-green color deficiencies. People with normal eyesight should be able to see the figure without any problem. Those with color blindness, though, will usually see another figure, or nothing else but spots.

Depending on what the viewer sees, the Ishihara test will serve to indicate whatever form of color blindness the patient should be suffering from.

The Ishihara test is usually conducted in a room with adequate lighting, for best results. For home-testing, or when using electronic cards in the form of graphic photos stored in computer, the viewer must remember one simple rule: the figure must be kept at eye level at all times during the test. For best results, the Ishihara test is best conducted with the viewer seated at around seventy-five centimeters away.