Aerospace Engineering Practice Exam

The opening that regulates how much light enters is the pupil. It’s the adjustable hole through which light passes to reach the inner eye. The iris surrounds this opening and contains muscles that change the pupil’s size: in bright light the sphincter muscles contract to make the pupil smaller, limiting light; in dim light the dilator muscles cause the pupil to widen, letting more light in. The retina is the light-detecting layer at the back of the eye, not an opening, and the cornea is the clear front surface that helps bend light but doesn’t regulate the amount entering.