Who uses eyeglasses?

People who have refractive errors, such as nearsightedness (myopia), farsightedness (hyperopia), or astigmatism, may need to wear eyeglasses to correct their vision. Refractive errors occur when the shape of the eye or the cornea (the clear outer layer of the eye) prevents light from focusing properly on the retina (the light-sensitive tissue at the back of the eye). Eyeglasses work by changing the way light enters the eye, so that it focuses correctly on the retina. This can improve visual acuity (the ability to see clearly) and reduce eyestrain. In some cases, eyeglasses may also be used to protect the eyes from ultraviolet (UV) rays from the sun or to correct other eye conditions, such as strabismus (crossed eyes) or amblyopia (lazy eye).