One of the main reasons my cats almost died was from dry food. It was Meow mix a good and expensive brand and it effects their kidneys and bladders. My cat Fluffy has never recovered completely. The vet told me that dry food is too acidic and should not be fed to animals. I give them some once a day only and in small amounts. Also I put ground up veggies in the meat I feed them to keep them balanced. They hate rice alone but if I mix it with some chicken and some zuchinni and carrots and then mix it all with diluted milk they like that. So in other words you might consider to make your food homemade. Many sites on that. Olive leaf builds the immune system and if I had to give them anything, that would be the one. Also for eyes you can put some camomile tea dipped in cotton balls and day their eyes and that will clear up in 3 days.