clownfish eye problem

[susz]

I need some advice, my husband is in the hospital, and when I came home last nite the percula clown fish had one eye that was a . It looks better this morning and is only on one side, should I leave the lights off today to help the fish recouperate? It is a nano tank with mushroom polps and a zooaind colcoly, I am using live rock, hang on filter . I just did a water change 3 days ago and also changed the charcoal filter. I have had the tank for 1year. this is a reef tank so he is the only fish, he wouldn't eat last nite,