What is a toric lens?

While a regular lens is shaped like a slice from a ball, a toric lens is shaped like a slice from the side of a donut, with a hole or depression in the middle area. Toric lenses are used in contacts and glasses to correct astigmatism.

For corneal astigmatism, the way light is refracted within the eye differs between the horizontal and the vertical planes, creating a difficulty in seeing fine details or causing vertical lines to appear tilted. By using a toric lens, doctors can change the way light is bent at each point of the lens, matching the astigmatism perfectly.