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.
Next, light rays pass through an opening in the iris (colored part of the eye), called the pupil. The iris controls the amount of light entering the eye by dilating or constricting the pupil. In bright light, for example, the pupils shrink to the size of a pinhead to prevent too much light from entering.