Last night i noticed when pippin fell asleep on my stomach, that one of his eyes looks like it might be hurting him. He is blinking them at sperate times, and keeps one eye open very wide, and the other squinting. its the same eye, he isnt changing, and it seems that he only opens the squinty one when i approach him, but the second he realizes there isnt danger he lets it shut half way again. is there something wrong with his eye that i should be worried about?