nosis was ty-pos OCA. Although this simple test showed that there were different types OCA, further studies have shown that the hairbulb incubation test is not very sensitive and has many false negative and false positive responses. As a result, the hairbulb incubation test is no longer used in the evaluation of and individual with OCA.In the 1980s the classification of OCA was expanded using very careful skin, hair, and eye examinations. The reason for this was the knowledge that there were more than 50 gene loci that controlled pigmentation in the mouse, and it was suggested that careful studying of the skin, hair, and pigmentation of individuals with OCA could help identify the human equivalent of each of these genes. A number of types of OCA were identified, including platinum OCA, minimal pigment OCA, yellow OCA, temperature-sensitive OCA, autosomal recessive ocular albinism and brown OCA, and it was hoped that each would be caused by a different gene. In the 1990s, we were able to identify the genes involve in most types of OCA, and have found that the classifications based on hair, skin and eye color is not accurate and that it was better to classify OCA types based on the specific gene involved. People who have oculocutaneous albinism are unable to produce melanin; they have white, yellow, or yellow-brown hair, very light eyes (usually blue or grayish rather than pink), and very fair skin. It is a common notion that people with albinism must have red eyes, but in fact the color of the iris varies from a dull gray to blue to brown. Under certain lighting conditions, little pigment is visible. This reddish reflection comes from the retina, which is the surface lining the inside of the eye. This reddish reflection is similar to that which occurs when a flash photograph is taken of a person looking right at the camera, and the eyes appear red. With some types of albinism the red color can reflect back through the iris as we...
