Even with the most sophisticated instrumentation it is difficult to examine the back of the eye through a small pupil. Imagine examining the contents of a closet through a keyhole. An individual would likely see only a small area in the rear of the closet. Dilating drops enlarge the pupil and allow full visualization of the back of the eye. Diseases such as glaucoma, diabetic retinopathy, macular degeneration, cataracts, vascular disease, tumors, and retinal detachment require pupil dilation for detection and proper evaluation.