Hi Lois, herpesvirus is certainly one possibility, as herpesvirus can cause viral conjunctivitis. If it tends to resolve on its own after some time and you don’t see thick or discolored eye discharge (and it occurs in both eyes) that makes it more possible. Unfortunately, there is very little we an do for herpesvirus flare-ups if they occur and they will occur off/on for the life of the cat. Some veterinarians still use lysine supplements and do believe they help individual patients. They are not as widely used as they once were about 10-15 years ago, but you can read our article on lysine supplementation for cats and see if it’s worth trying. If it’s been going on longer than usual, or there is thick or discolored discharge, a bacterial infection can sometimes become involved. If your cat allows, you can try a warm compress over the eyes using a warm washcloth for 5 minutes twice a day.