A nearsighted eye sees near objects within a certain range very clearly while distance vision appears blurry at all times.
An estimated 70 million people in the U.S suffer from this condition. Most often caused when the eyeball is too long for the focusing power of the lens and cornea, nearsightedness creates an overpowered eye which causes images to reach true focus in front of the retina.
Correction requires a "minus" lens to "weaken" the eye optically to permit clear distance vision. Near-sightedness
can usually be easily corrected with glasses or contact lenses.
Farsightedness, or hyperopia
, occurs when an eyeball is too short for the focusing power of the lens and cornea. This causes light rays to focus behind the retina.
As a result, the eye sees distant objects more clearly while near objects appear blurred. It is a condition in which your eye is underpowered. Correction requires a "plus" lens containing additional optical power to permit sharp vision of near objects.
Astigmatism is a common visual distortion caused by an irregularly shaped cornea. The surface of the cornea is toric, oblong in shape like a football, instead of perfectly round like a basketball.
Light rays passing through an oblong cornea bend unequally, causing two focusing points. Consequently, vision is blurred at most distances.
Today, there are a wide range of contact lens options for correcting astigmatism even for patients with the severe astigmatism
If you're 40 or older and have noticed it's been getting harder and and harder to read small type, you may have a common vision condition called presbyopia. Fortunately, reading or bifocal eyeglasses are not your only option.
Today, we can correct for presbyopia
with either glasses or multifocal contact lenses to let you see clearly near, far, and everywhere in between.