Astigmatism: How It Works, Explained Simply

Video Transcript

Astigmatism is a very common focusing difference. It is not a disease, and most people have at least a small amount. An evenly curved cornea is shaped like a slice of a basketball. It is equally curved in every direction. With astigmatism, the cornea is curved more in one direction than the other, more like the side of an American football. Because the two directions bend light by different amounts, the eye forms more than one focal point instead of a single sharp one. The result is blur or a stretched, doubled look at all distances, near and far, sometimes with streaks around lights at night. It usually occurs alongside nearsightedness or farsightedness, rather than on its own. Most astigmatism is simply the natural shape you were born with. It can also come from the lens inside the eye, and less often from a corneal condition. It is corrected with glasses or toric contact lenses that have different power in different directions, and laser surgery is an option for many adults. This video is for general education only. It is not medical advice. Ask your eye doctor what's right for you.