Astigmatism is a defect in the shape of your eye’s lens or cornea, which is the transparent dome that sits atop your iris and pupil. In healthy eyes, both your cornea and lens possess a smooth and equal curvature, like a ping pong ball. This condition, which fosters normal eyesight, is referred to as astigmatism.

A cataract is a cloudy film over the lens of your eye that adversely affects your vision. Cataracts are typically a result of aging, and they’re more common in the elderly. According to the National Eye Institute, by the age of 80, more than half of all Americans have cataracts or have been treated surgically for cataracts.