What is purple eye disease?

Purple eye disease, also called Alexandria's Genesis, is a fictional genetic condition that is supposedly named after a woman born in 1329 in London. Individuals afflicted with the mutation develop purple eyes, don't have any body hair and never gain weight.

These fictional purple-eyed individuals also never menstruate, but are fertile, and also rarely have bowel movements. They have very pale skin but don't get sunburned. They never get sick and live for an exceptionally long time. The condition is reported to have been invented in fan fiction stories to explain the existence of perfect purple-eyed people in the stories.