Albinism is characterised by the absence of the pigment
melanin in the eyes, skin, hair, scales, or feathers. It
arises (13)---- a genetic defect and occurs in humans
and other vertebrates. (14)---- they lack the pigments that
normally provide protective colouration against the sun’s
ultraviolet rays, albino animals rarely survive in the wild.
Humans (15)---- certain albino animals (e.g. rabbits) for
their appearance for a long time. In humans with
generalised, or total, albinism, the (16)---- person has
milk-white skin and hair; the iris of the eye appears pink,
the pupil red. Vision abnormalities (17)---- astigmatism,
nystagmus (rapid involuntary oscillation of the eye), and
photophobia (extreme sensitivity to light) are common.