Why would my cat be losing hair above her eyes to the point of only raw skin left?

Because she is getting old. It is possibly from a food allergy. Check for little tiny hives (rash) on her ears, above her eyes and on her belly. Hives are a sure sign of a food allergy. In that case, changing her food will probably help. If you do not see hives, take her to the vet. Cats do not, and I repeat, do not lose their fur from aging!