Polar Bears don’t have albinism. They just look like it. Their skin is black (to keep them warm) but it is covered with a thick layer of white fur. There is more to albinism that looking white. It all has to do with genetics.
Unlike my friend here, I am an albino. Some people like to distance themselves from the condition and say they have albinism. But I’m old and I’ve been an albino for a very long time. It is part of my identity.
Although fairly common in birds, albinism is a rare genetic condition in humans. Genes impact structures, not behaviors directly. In the case of albinism, there is a recessive autosomal gene which governs the presence-absence of melanin (a natural pigment).
Autosomal means the gene is not on the X or Y chromosomes. Consequently, albinism is about evenly split between males and females. Recessive means the condition can be carried for many generations but isn’t expressed until two carriers of the gene mate.
The genetic jackpot results in a lack of pigment in the skin, hair and eyes. This lack of pigment causes white hair (not gray or blonde). It is not easy to fit in among a crowd when you have white hair but the consequence is mostly decorative. Being an albino gives you pretty hair, feathers or fur (depending on the species).
In humans, the primary disadvantage of no pigment in the skin is the increased likelihood of severe sunburns and cell damage. Albinos have skin that is pale (lack of melanin) and pink (from underlying blood vessels). In other animals, the lack of pigment in the skin, fur and feathers can be fatal. There is no protection from UV radiation and predators can easily spot you.
The lack of pigment in the eyes creates a lot of problems with vision, particularly in humans. Melanin does more than provide coloration. It is involved in the development of the visual system. No melanin produces an underdeveloped retina and optic nerve. The receptors don’t produce high quality images and don’t effectively transport those images to the occipital lobe of the brain for processing.
Albinos also have less rods (poor night vision), more unstable muscles (causing the jittery movements of nystagmus), and no light absorption between the visual receptors (giving a halo lighting effect like a lens flare).
Here is some more about this condition:
- Disneyland, Albinism & Psychology
- Albinism: A Primer
- Stupid Questions About Albinism
- Albinism In The Movies
- Albino Eyes (videos)
For more information about albinism, I’d suggest:
NOAH (national organization for albinism and hypopigmentation)