(1) Treat the eye with an antibiotic ointment and antihistamines, such as Benadryl (diphenhydramine).
(2) Wash out the eye with plenty of water. An eyewash station is available in every veterinary clinic; ask your veterinarian to show you how to use it. If there’s no facility nearby, pour a cupful of warm water into one hand and half a teaspoon of baking soda into another. Gently massage this mixture around inside and outside both eyes until it stops stinging (don’t put anything in your eyes!). Then flush them for several minutes with running water from an outdoor faucet or kitchen sink. Examine carefully afterward: Look for any foreign particles that may have been left behind by the kitten (“foreign body” conjunctivitis); remove as much as possible using tweezers or forceps, then wash well again before putting drops in them if necessary — see above — according to directions on the bottle label.