Personal Best Health Wellness - Why you need glasses

There are 3 primary reasons:

MYOPIA (nearsightedness) ­ when distant objects are blurred. It is caused by the combined power of the cornea and lens of your eye being too great in relation to the length of the eyeball. To see distant objects clearly: The focusing power of your eye must be reduced by a concave (minus) lens. Myopia tends to be inherited, usually appears around puberty and increases progressively until the early 20s, when it stabilizes.

HYPEROPIA (farsightedness) ­ when near objects are hard to see. It is caused by the eye being too short from front to back, so that images are not clearly focused on the retina. To see close objects more clearly: Convex (plus) lenses cause the light from the close object to focus on the retina. Hyperopia tends to be inherited, but symptoms generally do not appear until mid-life as accommodation naturally declines. The more severe the problem, the lower the age at which the problem appears.

PRESBYOPIA (the progressive loss of accommodation, or the ability to naturally correct near vision) ­ when the focusing power weakens with age, until around 65, little or no focusing power remains. Symptoms generally appear around 45 when the eyes cannot accommodate within nor-mal reading distance. To improve focusing ability: Convex (magnifying/reading) lenses are used.