Do the irises (color) of your eye serve a purpose for vision, or is it soley the pupil?

Question

I was just wondering if anyone knew. My sister wears these cheap plastic colored contacts that don't impair her vision at all and my husband's contacts cover his irises and his pupils. I've never had vision issues (my vision is 20/10).

Answer 1

The irises are in the eye because they serve to make the pupil bigger or smaller to let in more or less light. I don't they actually help with seeing things in any way at all.

Answer 2

They don't have a direct correlation to vision other than changing pupil size as stated above, but if you get atrophy of the iris and too much light gets in it could cause problems...also if there are holes in the iris where none should be, you might get double vision.