What type of lens is typically used to correct astigmatism?

Toric lenses are specifically designed to correct astigmatism, which is a refractive error caused by an irregular shape of the cornea or lens. Unlike spherical lenses that have a uniform curvature, toric lenses have different curvatures in different meridians of the lens. This unique shape helps to focus light properly on the retina, compensating for the uneven refractive power associated with astigmatism.

The purpose of a toric lens is to provide clear vision by addressing the unique prescription needed for each eye, as astigmatism often requires a combination of correction for both nearsightedness or farsightedness along with the specific cylinder power for astigmatism.

In contrast, bifocal lenses are designed for individuals who need two different optical powers, typically for near and distant vision. Monofocal lenses have a single optical power throughout the entire lens and are generally used to correct either nearsightedness or farsightedness, but not specifically astigmatism. Progressive lenses offer a gradual change in lens power for multifocal vision without any visible lines, but they also do not specifically address astigmatism in the same targeted manner as toric lenses do.