Myopia is corrected through use:

Question

Accepted Answer

The correct option is 2:

Myopia, commonly known as nearsightedness, is a refractive error where light from distant objects focuses in front of the retina instead of directly on it. This results in blurred vision for distant objects, while close objects appear clear. This condition typically occurs because the eyeball is too long or the cornea has too much curvature. To correct this, we need a lens that diverges the light rays before they enter the eye, pushing the focal point back onto the retina. Biconcave lenses are diverging lenses, meaning they spread out parallel light rays that pass through them. By placing a biconcave lens in front of a myopic eye, the light rays are diverged, effectively shifting the focal point backward to land precisely on the retina, thereby restoring clear distant vision.

The incorrect option is 1: Biconvex lenses

Biconvex lenses are converging lenses, meaning they cause parallel light rays to converge to a single focal point. If used to correct myopia, biconvex lenses would further converge the light rays, making the focal point fall even further in front of the retina, thus worsening distant vision.

The incorrect option is 3: Cylindrical lenses

Cylindrical lenses are used to correct astigmatism, a refractive error where the eye has different focusing powers in different meridians. They are designed to focus light along a single line, not to diverge or converge light uniformly. Therefore, they are not suitable for correcting the spherical refractive error present in myopia.

The incorrect option is 4: Bifocal lenses

Bifocal lenses contain two different optical powers, typically for correcting both distant and near vision problems in individuals with presbyopia (age-related farsightedness) in addition to other refractive errors. While a bifocal lens might incorporate a biconcave lens for the distance portion, "bifocal lenses" as a general type are not the specific optical component that corrects myopia. The corrective element for myopia within a bifocal lens would still be the concave power.