Multiple choice Which of the following lenses should be used to correct the defect of astigmatism? Cylindrical lens Concave lens Convex lens Bifocal lens Reveal answer Fill a bubble to check yourself A Correct answer Explanation Astigmatism is a refractive error caused by an irregularly shaped cornea or lens, which prevents light from focusing properly on the retina. A cylindrical lens is used to correct this by focusing light differently in different meridians.