Add the iris and pupil, paying attention to their proportions. Shade the sclera lightly to give it depth, and incorporate reflections on the surface of the eye. Create texture for the eyelashes ...

Nocturnal animals tend to have proportionally bigger eyes than humans do. They also tend to have pupils that open more widely in low light. So, at the outset, nocturnal eyes gather more light than ...

pupil movement might one day be used to detect disorders such as insomnia and post-traumatic stress disorder, or even a comatose patient’s recovery. We haven’t yet figured out if eyes are ...