Astigmatism is corrected by a lens featuring what type of power?

Astigmatism is a refractive error characterized by an irregular shape of the cornea or lens, which leads to blurred or distorted vision. To correct astigmatism, a lens with cylinder power is used.

Cylinder power is essential because it provides the necessary correction in one meridian while allowing a different prescription in the perpendicular meridian. This design helps in compensating for the uneven curvature of the eye's surface, effectively focusing light onto the retina.

In contrast, plus power lenses are typically used to correct hyperopia (farsightedness) and minus power lenses to correct myopia (nearsightedness). Prism power, on the other hand, is used to address issues related to binocular vision or eye alignment rather than refractive errors. Therefore, the appropriate correction for astigmatism specifically relies on the use of cylinder power, making it the correct choice.