When do albinos occur?

Albinos -occur when there is an absence of yellow, red, brown or black pigments in an animal's eyes, skin, scales, feathers or hair. This peculiarity can be passed on from one generation to another. But albino animals do not often survive in the wild, because their normal colouring is designed to protect them against radiation or enemies. In the case of human beings albinism is caused by the absence of the pigment melanin. It varies from complete albinism involving skin, hair and eyes to localized albinism or spotting. The complete human albino has milk white skin and hair. The irises of his eyes appear pink, while his pupils take on a red hue from light reflected by blood in the in pigmented structures underneath. There is one complete albino for every 20,000 people.