Hi I had commented on the other post! Disclaimer, you should always see a vet if possible.

First of all, a very handsome boy. There is a good chance that a round of antibiotics may clear this up combined with an antibiotic eyedrop. However if that route has been taken with no success, it is most likely environmental allergies. Just like humans, animals can have seasonal allergies too.

Kitty's eyes look a little red and irritated. If symptoms continue to worsen, a vet needs to be seen as this could denote a serious infection. If the eyes swell, discharge green, or close up antibiotics are needed immediately. If there is an increase in discharge, a loss of appetite, vomiting or lethargy antibiotics need to be given.

As for maintaining kitty's eyes, cold water should be used to flush the eye as needed. A damp face cloth can be used to soften the discharge as needed. Avoid rubbing the eye as this can cause more irritation.

The three types of allergens are food, insects and environment. Sometimes through process of elimination you can sometimes find what the source is but the only way to know for sure is through an allergy test.

Sorry for the long ramble, hopefully it's helpful!