Colour Blindness is a vision defect characterized by the inability or decreased ability to see colour or perceive colour differences. The most common cause of colour blindness is the deficient development of retinal cones. This is usually an inherited disease. Symptoms are the inability to see colours or differentiate between colours. Some people with colour blindness can see only red colour or only blue or only green colour. Complete colour blindness is called Achromatopsia.
HOW IS COLOR BLINDNESS DIAGNOSED?
The Ishihara color test, which consists of a series of pictures of colored spots, is the test most often used to by ophthalmologists to diagnose red–green color deficiencies. A figure (usually one or more Arabic digits) is embedded in the picture as a number of spots in a slightly different color, and can be seen with normal color vision, but not with a particular color defect. The full set of tests has a variety of figure/background color combinations and enable diagnosis of which particular visual defect is present. The anomaloscope, described above, is also used in diagnosing anomalous Trichromacy. Besides the Ishihara color test, the US Navy and US Army also allow testing with the Farnsworth Lantern Test. This test allows 30% of color deficient individuals, whose deficiency is not too severe, to pass.
Another test used by ophthalmologists to measure chromatic discrimination is the Farnsworth-Munsell 100 hue test. The patient is asked to arrange a set of colored caps or chips to form a gradual transition of color between two anchor caps.
The HRR color test (developed by Hardy, Rand, and Rittler) is a red-green color test that, unlike the Ishihara, also has plates for the detection of the tritan defects.
Most clinical tests are designed to be fast, simple, and effective at identifying broad categories of color blindness. In academic studies of color blindness, on the other hand, there is more interest in developing flexible tests to collect thorough datasets, identify copunctal points, and measure just noticeable differences.
HOW IS COLOR BLINDNESS TREATED?
There are no proper treatments available for this issue. A recent test and research is under process which may have positive results, but there are no conclusions yet.
DID YOU KNOW?
This is a genetic problem and usually passes on. So if your mother had it and you got it, chances are that your kid will get it too.