my cat's eye hurts her,red and stingy looking

My 5 year old female cat has an eye ailment that comes around 4 times a year, ongoing for years. I have been to a vet ,usually for a $50 fee,they give me oilment for the cat's eye. The cat lives exclusively indoors and her 3 year old daughtercat lives in identical conditions and has no problems with her eyes. all have thier annual shots,etc. i believe its the same eye all the time,but i cant be sure


this week the eye problem is back. the eye is usually particially closed by the cat, dark red,looks like it stings.


Besides going to the vet,is there oilment i can buy online or at a pet store to reduce the pain&discomfort for the cat? Im aware the CAUSE of the problem should be found but until the time comes,i want to relieve the cats discomfort.


special note; i live in a remote area,vets are in short supply and appear to be not that responsive to feline health patients.

thanks

Cats can develop very serious eye problems, and one example would be glaucoma. Are there any large cities nearby where you might be able to have your cat's eye evaluated by a specialist?

i will be looking but could not find one before(specialist),the nearest vet place i know i can trust is about a 2.5 hour drive. most vets in my area are actually large animal-type vets(horse,etc.) and i suspect some of the vets do not even have proper credentials to be a vet(a post for another day perhaps).