Going on about 2 weeks now two of My 6 week old chicks have been lethargic and keep eyes closed throughout the day. They even walk around the coop with their eyes shut. They will occasionally peek out their eyes so I know they can open. Their is no discharge from their eyes, nose, or beaks and their poop seems normal. They seem to eat and drink normally and are still growing. They are fed medicated chick starter and have electrolytes in their water. Any suggestions/advice on what could be going on would be great!