My old boy is a boxer x rottie, he's 11, and the vet suspected he had a stroke end of 2019. The last couple of days his eyeball has looked odd, a quick chat with a veterinary nurse over the phone has suggested it's a third eyelid? He has an video appointment booked in today at 5, but it's playing on my mind, to me it doesn't seem like a typical third eyelid, I guess I'm just after some reassurance really that he's ok, and it's normal and he's not going blind? Added pictures of my beautiful boy