CoreCHI Healthcare Interpreter Standards of Practice (SOP) Exam Practice

The colored part of the eye that controls how much light gets in is the iris. The iris contains muscles that tighten or relax to change the size of the pupil, the opening through which light enters. In bright light, the iris makes the pupil smaller to reduce light; in dim light, it widens the pupil to let in more light. The retina sits at the back of the eye and senses light after it passes through the pupil, sending signals to the brain, while the cornea is the clear front surface that helps focus light. So the iris is the part that regulates light entry.