This even applies to anime. In modelling a head, should I not think about the size of the eyes? It seems to me I should not be too concerned with perfect globes, but rather convex shapes.And then worry about shaping the skull around those big peepers. Opposite of what I’ve been recently working on. Paperman is an excellent example. Her eyes are Huge in comparison to His. Yet you buy it. POV, certainly.
I would try using a somewhat flattened UV sphere, then use an armature to move the iris and pupil over the surface of the sphere, assuming it is going to be animated. I’m sure there are other methods for this. I suppose some people would use an animated texture for the iris/pupil.