Yes, they're literally sunglasses for cats. No, we are not joking.
There are a lot of potential reasons why you may want or need sunglasses for your cat. Cats, like humans, have very sensitive eyes. Unlike humans, cats can dilate their pupils at will to reduce the amount of light that enters the eye. However, this does not make them immune to the blinding glare of the sun. Alternatively, maybe you just want your cat to look cool. Maybe you've always wanted your cat to cosplay Morpheus or perhaps.... Hairy Pawter (sorry we couldn't resist). Or maybe, just maybe, you've run out of creative ways to irritate your cat and you want to try something new.