When two people fuse through the fusion dance, or the potara earrings, the newly fused product leans to the characteristics and personalities of the two former subjects, but they do not submit to their control. The only character who ever submitted to control was super Gogeta, who had no choice.
The pupil is a hole located in the centre of the iris of the eye that allows light to strike the retina. It appears black because light rays entering the pupil are either absorbed by the tissues inside the eye directly, or absorbed after diffuse reflections within the eye that mostly miss exiting the narrow pupil.
The iris is the colored part of the eye that helps regulate the amount of light that enters the eye. The pupil is the dark aperture in the iris that determines how much light is let into the eye. The lens is the transparent structure inside the eye that focuses light rays onto the retina.