Myopia, or nearsightedness, occurs when the cornea is too steep and/or the eye
is too long. This causes light to focus in front of the retina, resulting in blurry
distance vision. Myopia is a common condition that affects nearly one third of the
U.S. population. The condition often worsens as the body grows, but it usually stabilizes
in adulthood.
Hyperopia (Farsightedness)
Hyperopia, or farsightedness, occurs when light rays entering the eye are focused
behind the retina, rather than directly on it. This may happen because the eyeball
of a farsighted person is shorter than normal and/or the cornea is flatter than
normal. Many children are born with hyperopia, and some “outgrow” it as the eyeball
lengthens with normal growth.
Farsightedness is a fairly common vision problem. Initially, people with hyperopia
can see distant objects very well, but have difficulty seeing objects up close.
Later in life, their distance vision deteriorates as the lens loses its ability
to accommodate. Often this condition is not detected early in life because the young
eye is able to compensate by altering the internal lens of the eye.
Sometimes people confuse hyperopia with presbyopia. Presbyopia is difficulty
seeing near objects as a result of an age-related decrease in accommodation.
Astigmatism
Astigmatism occurs when the cornea is oblong—in other words, it is shaped more like
a football than a basketball. The oblong shape causes light rays to focus in two
places on the retina, causing blurred vision.
Astigmatism may also accompany nearsightedness or farsightedness, and can get
worse with age. A small amount of astigmatism may cause only slightly blurred vision.
Sometimes uncorrected astigmatism can lead to headaches or eyestrain.
Presbyopia
Presbyopia is the loss of accommodation over time. Accommodation is the eye’s
natural ability to bring near objects into focus.
For those with good unaided distance vision, reading glasses are the simplest
way to correct near vision. Those who also require distance correction often choose
bifocals. For patients who would rather not wear glasses, multifocal contact lenses
or refractive surgery are options.
