Reading glasses are made from which type of lenses? (Pre) 2000

Explanation

Reading glasses are generally made from convex lenses. Such lenses are useful in hypermetropia (long-sightedness) and in age-related defective near vision called presbyopia. With increasing age, the power of accommodation of the human eye decreases. In most persons, the near point shifts farther away. Without corrective spectacles, they find it difficult to see nearby objects clearly and comfortably. This defect is called presbyopia. In hypermetropia also, a person cannot see nearby objects, but the reason is different—for example, the eyeball may be shorter than normal or the lens may have less focusing power, due to which the image forms behind the retina. ## Page 7