I have 3 cats of 5, 4 and 2 years old, all rescues. Our youngest one we got as a kitten off the street, he is now a strong and long 23 pounds ball o' fire, but he has been having on/off eye problems for maybe 6 months. One of his eye he tends to keep closed for long periods, like it hurts to keep it open. Then his eyes returns to normal for a while. We checked both eyes and see no swelling/redness, plus there is no discharge on the affected eye. He didn't have this problem as a kitten. He's a big player so for a while we suspected he might have gotten hurt while playfighting with his smaller siblings, but still, no signs of infection of any kind in his eye! We're quite puzzled here Anyone have an idea of what could possibly be going on with him?