What type of lens is designed to correct astigmatism and has refractive power in one meridian only?

A lens designed to correct astigmatism is known as a cylindrical lens. This type of lens has refractive power that differs between its meridians, allowing it to address the asymmetrical curve of the cornea or lens that characterizes astigmatism. The cylinder's power is concentrated in one particular meridian, enabling it to effectively correct the specific visual distortion that occurs when light rays enter the eye at different angles.

In contrast, a spherical lens uniformly bends light in all directions and is primarily used to correct nearsightedness or farsightedness. A bifocal lens, which contains two different optical powers to help with both distance and near vision, does not specifically address astigmatism. Lastly, a prism lens is used to correct issues related to eye alignment and does not specifically serve the purpose of correcting astigmatism. Thus, the cylindrical lens is the appropriate choice for effectively correcting astigmatism due to its unique refractive power in only one meridian.