Can I treat a cat eye infection at home?

You have to be careful with that. You don't want to grab things out of your cabinet, even if the issue is similar to an old problem. Don't be like, "Oh, my cat had this before, let me get these meds from before," because it may not be the same issue, or there may be something else going on that we need to address. If your cat will even let you, the only thing that you can do is to use sterile saline eyewash to flush an eye out. But the answer will always be to see a veterinarian. We can make sure that it's not something we need to treat specifically, and we'll treat it correctly.