How come in summer your green eyes get bright golden rings around the pupil?

I have green eyes with gold flecks around the pupil also. But it is just that the gold only shows in bright light, which constricts the pupil sufficiently for the inner part of the iris to show. In dimmer light, the eyes dilate (pupil becomes wider) so only the outer part of the iris is visible. Another possibility is a person with naturally golden eyes, but wearing green contact lenses. With tinted contacts, the artificial color does not go all the way to the center (or the wearer would see everything as being green, if it covered the pupil). So when their pupils are constricted, a ring of their natural color shows through the clear center of the contact lens near the pupil.