I'd buy that except that the umbrella term "optical illusion" covers a lot of ground from simple physical things like a blind spot, through those color invertin

I'd buy that except that the umbrella term "optical illusion" covers a lot of ground from simple physical things like a blind spot, through those color inverting things, to weird ones that involve computation, where you can't see all 16 dots, or the jagged blocks "heal" themselves. Cats perceiving squares is clearly not optical, but rather computational.