<P> Eye color outside of the iris may also be symptomatic of disease . Yellowing of the sclera (the "whites of the eyes") is associated with jaundice, and may be symptomatic of liver diseases such as cirrhosis or hepatitis . A blue coloration of the sclera may also be symptomatic of disease . In general, any sudden changes in the color of the sclera should be addressed by a medical professional . </P> <P> Aniridia is a congenital condition characterized by an extremely underdeveloped iris, which appears absent on superficial examination . </P> <P> Normally, there is a thick layer of melanin on the back of the iris . Even people with the lightest blue eyes, with no melanin on the front of the iris at all, have dark brown coloration on the back of it, to prevent light from scattering around inside the eye . In those with milder forms of albinism, the color of the iris is typically blue but can vary from blue to brown . In severe forms of albinism, there is no pigment on the back of the iris, and light from inside the eye can pass through the iris to the front . In these cases, the only color seen is the red from the hemoglobin of the blood in the capillaries of the iris . Such albinos have pink eyes, as do albino rabbits, mice, or any other animal with a total lack of melanin . Transillumination defects can almost always be observed during an eye examination due to lack of iridial pigmentation . The ocular albino also lacks normal amounts of melanin in the retina as well, which allows more light than normal to reflect off the retina and out of the eye . Because of this, the pupillary reflex is much more pronounced in albino individuals, and this can emphasize the red eye effect in photographs . </P> <Table> <Tr> <Td> </Td> <Td> This section needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (November 2012) (Learn how and when to remove this template message) </Td> </Tr> </Table>

Where do we get our eye color from