Farsightedness (hyperopia)
What
is farsightedness?
Farsightedness is a vision problem that usually causes near vision to
be blurred while distance vision remains normal. But farsightedness can
affect your vision in different ways, depending on your age and the amount
of farsightedness you have.
Young individuals with mild or moderate farsightedness can often see clearly
at all distances. Instead of causing blurred near vision, their farsightedness
may cause only headaches and eyestrain. Older individuals even those with
relatively mild farsightedness may find that farsightedness causes blurred
vision at all distances (both near and far).
Farsightedness is often confused with presbyopia. Presbyopia is the normal
age-related loss of near focusing ability due to hardening of the crystalline
lens inside the eye. This change usually becomes noticeable after age
40 and gets progressively worse over a period of several years.
Presbyopia
is corrected with reading glasses (for people who need no corrective lenses
for distance vision or who wear contact lenses for distance vision) or
with bifocal, trifocal, or progressive eyeglass lenses (for people who
already wear eyeglasses).
Farsightedness, on the other hand, usually occurs early in childhood and
remains relatively constant throughout a person’s lifetime. Everyone
experiences presbyopia (if they live long enough). Not everyone experiences
farsightedness.
The medical term for farsightedness is hyperopia.
Clear vision requires the cornea and the lens of the eye to focus light perfectly on the retina. For this to happen, the cornea and lens must have exactly the right amount of curvature so they can focus light within the length of the eyeball.
Farsightedness occurs when the cornea (or lens, or both) is not curved enough to bring light to a focus within the length of the eyeball. In some cases, the cornea and lens have a normal amount of curvature, but the eyeball is smaller than normal and therefore does not provide enough front-to-back distance to match the focus distance of the cornea and lens.
Mild farsightedness may produce no symptoms in children and young adults. Moderate or severe farsightedness in all age groups (and mild hyperopia in older adults and some younger individuals) can cause one or several of the following symptoms:
• Headaches (especially during and after reading and other close work)
• Eyestrain or fatigue (especially during and after reading and other close work)
• Blurred vision (especially up close)
• Poor concentration and/or reading comprehension problems in schools
How
is farsightedness treated?
Farsightedness can be corrected with eyeglasses, contact lenses or refractive
surgery.
