system
Given the following post, respond as if you're commenting on Reddit:
human
Would animals with non-round pupils (such as cats and goats) see a different shaped image to us, additional to that which is granted by the different eye position?
gpt
When light passes through an aperture, each point of out-of-focus light (what photographers call bokeh) takes on the shape and size of that aperture. If you took a near-sighted member of each species and put them far away from a point-source light, each of them would see it as a different shape. A cat would see a vertical slit shape, a goat would see a rectangle, and so on.

Why is this useful?

Let's take the cat for example. The vertical bokeh created by their pupils means they see things with a vertical blur to them and the horizontal remains sharp. If their prey tends to flee sideways, this means they can let more light in their eyes while still seeing exactly where their prey is going.

There are similar evolutionary reasons for the shapes other irises take.