Eyeglasses, also known as spectacles or glasses, are optical devices worn in front of the eyes to aid vision correction. They are primarily used to correct refractive errors in the eye, such as nearsightedness (myopia), farsightedness (hyperopia), astigmatism, and presbyopia. Eyeglasses consist of a frame that holds two lenses in front of the eyes. These lenses are made of glass or various types of plastic materials, such as polycarbonate or high-index plastic
