Color Blindness - Diagnosis
A variety of tests can be used to diagnose color blindness. The most common of these tests is the American Optical/Hardy, Rand, and Ritter (AO/H.R.R.) Pseudoisochromatic (pronounced SOO-doe-I-so-kro-MAT-ik) Test. This test includes the use of a plate covered with spots of one color (green or red, for example). In the middle of the plate is a figure, such as a number or letter, made of spots of a different color. A person with normal color vision can see the figure against the background. A color blind person cannot.
A similar test, the Ishihara test, uses eight test plates similar to those used in the AO/H.R.R. test. The person looks for numbers made up of dots of various colors on each plate.
A third test is the Titmus II Vision Tester Color Perception Test. In this test, a person looks into a viewing device at a series of figures on a black background framed by a yellow border. The test can easily be performed in a doctor's office. It is not considered to be a very accurate test, however, and can only test for red/green color blindness.
The first person to describe color blindness was the English chemist and physicist John Dalton (1766–1844). Dalton is famous because he was the first modern scientist to develop the atomic theory. However, Dalton was interested in many topics besides atoms. For example, he was keenly interested in meteorology (the study of the weather) and kept daily weather records for fifty-seven years. His records, published as Meteorological Observations and Essays, are among the most complete in all of scientific history. The first scientific paper Dalton ever wrote was about color blindness. He probably became interested in the subject because he, as well as his brother, was color blind. In honor of his research, the condition of color blindness is still sometimes called daltonism .
Comment about this article, ask questions, or add new information about this topic: