What is wrong with my cat's eye?

Cute cat!! It might be nothing. If the cat got a hair in it's eye or lightly scratched it then the eye will be fine in a few days. But cats can carry pink eye so make sure you wash your hands after holding her until it clears up. If the cat was scratch badly the third eye lid will be over the eye. It is a white eye lid under the normal eye lids. If the cat has a bad scratch it will need an antibiotic ointment to get over it. I would watch it for a few days. Make sure the cat does not go outside. It will probably clear up.