15 year old cat left pupil bigger than right

Cat Question: My cat is almost 15 years old.  I just noticed today that his left pupil is noticeably bigger than his right.  Also noticed he shakes a little bit when he is still.  You have to look at him and not just glance to notice it.  Does he need to see a vet or is he on his last leg and make him comfortable? he eats and drinks and uses that litter box fine still, (I watched him like a hawk when I noticed the eye) His eye isn't watery or there isn't any color change.  There is a little buldging but nothing horrific. he walks fine, he looks at you when you say his name.

Hi Denny,

Sorry to hear about your cat.

Please check your cat over carefully.  Sometimes only one enlarged pupil could be cause by neurological problems or trauma, like from a fall.

Could your cat have fallen off of anything?

I have seen cases like this where the next day, the cat is back to normal.

If you cat changes levels of consciousness though I would see a vet.