[beverlykaye (OP)]

I have a cat the is a mix between Siamese and something else, but I notice she has round pupils. Can anyone tell me why hers is round and other cats eyes are slitted?

[alancalverd]

Round pupils are characteristic of "big cats" and many oriental breeds of domestic cat. They seem to be associated with "canine-like" behaviours compared with the typical feline behaviour patterns of a small European moggie.

IIRC the slit pupil makes kittens very sensitive to horizontal movement but requires exceptional retinal sensitivity for night hunting, whereas the round-pupil cats tend to hunt by day and  by pouncing on static prey rather than swiping moving objects.