Which type of lens is designed to correct astigmatism?

The spherocylindrical lens is specifically designed to correct astigmatism, which is a refractive error caused by an irregular shape of the cornea or lens of the eye. This lens has both spherical and cylindrical components; the spherical part corrects for myopia (nearsightedness) or hyperopia (farsightedness), while the cylindrical portion corrects the blurry vision caused by the uneven curvature of the eye.

In contrast, the other types of lenses serve different purposes. Bifocal lenses are intended for individuals who need correction for both distance and near vision, featuring two distinct optical powers but not addressing astigmatism specifically. Monofocal lenses provide a single optical correction for either distance or near vision, lacking the dual correction needed for astigmatism. Progressive lenses, while offering a gradual transition between different focal strengths for distance, intermediate, and near vision, also do not specifically address the unique cylindrical corrections required for astigmatism. The design of a spherocylindrical lens addresses the unique visual needs of patients with astigmatism, making it the correct choice for this question.