My cat Riot's eyes always look like this. I'm not on any meds for him to get into, and neither is he. He's just always been that way. When his pupils are at the normal dilation for a cat, a vertical slit, I begin to fear for my own safety.

And no, I'm not choking him. If you look, I'm holding him across his front "shoulders", because he was fascinated by my iPhone and kept creeping forward when I tried to snap a shot of him.