Re: Pupil sometimes larger/smaller than other but not often
Oh. Well, then, not to scare you, but my kitty Reilly had that happen to his eyes fairly regularly. Reilly was born some time in early 1999 and we took him in when he was about 8-10mo old. He passed away last year. He had a severe problem going on for many years, I had always thought he was a 'klutzy' kitty, but when I noticed in 2004 that he was getting more and more uncoordinated I took him to the vet. She was stumped. Bloodtests didn't show anything wrong, but he was definitely having trouble with his motor skills, most noticeable in his back legs.
She offered several options, but I had to choose the one that cost the least, which was cortisone shots every 3-5mo. They did no good and over the years, Rei progressed from hesitating with every step of his back legs, to wobbling when he ran, to being too uncoordinated to run, to walking 10 steps and then suddenly sitting to the side because the muscles would give out, to only being able to make 2-3 steps before falling into the sitting position and finally to having to drag himself on the carpet with his front paws. The vet consulted with her peers and the unanimous consensus was a tumor in his spine...so no amount of treatment would have been able to save him. I'm glad I didn't opt for the expensive treatments, but with our vet we were able to give him many years of love and enjoyment by accomodating his disability.
I never did ask or find out about his pupils being different sizes, but I don't think it was affected by his health problems of his back legs. Perhaps you could call your vet office and ask about it, though I suspect most vet offices will ask you to bring the cat in for an exam to rule out any neurological problems.