The Doc is right, an optomitrist is not the way to go, they are not MD's. See an opthalmologist.
You need to see an ophthalmologist Eye MD. If you didn't see that type of "doctor" then see one.
If you saw one and you have no other symptoms in the eye or elsewhere then CT scan is not likely necessary.
Up to 5-6% of people have different size pupils and no other problems its called physiological ansicoria.
JCH MD
I would get it checked out, especially if they stay different sizes for a while. I don't want to scare you, but that happened to me 13years ago (I don't recall if it was reacting to light or not) but they started changing size, firt they thought it was 'cause I was using the nasal spray Afrin at the time, then a few weeks later they did a MRI to see if there was a cist behind the eye, but it was a brain tumor behind the eye. So, I would pay lots of attention to that eye.