The following is a summary of common eye conditions and their descriptions.
*FARSIGHTEDNESS (HYPEROPIA) - this is a condition in which
distant objects are usually seen clearly but close ones appear blurred.
Farsightedness requires your eye's internal focusing lens to involuntarily
exert extra effort to maintain clear distance vision and even greater
effort to see clearly at near. This added effort can cause fatigue,
eyestrain, headaches, aching or burning eyes and blurred vision,
especially after a lot of near work. A child may pass a school's
vision screening and yet have significant farsightedness, which
may cause poor reading ability and decreased near efficiency. In
mild cases, a person's eyes may be able to compensate adequately
without requiring glasses. The need for glasses is mostly dependent
upon how strong an individual's focusing system is and whether a
person is having visual symptoms. Sometimes glasses are prescribed
to be worn mostly for near tasks.
*NEARSIGHTED (MYOPIA) - this is a condition in which near
objects are seen clearly, but distant objects appear blurry. Nearsightedness
is very common, affecting nearly 30% of the U.S. population. It
normally first occurs in school age children and continues to worsen
until around the age of 20. Nearsighted people often squint and
have trouble seeing chalkboards, televisions and road signs. These
people often complain of eyestrain, headaches and increased blurred
vision at night. In some cases, glasses are prescribed to be worn
mostly for distance vision.
*ASTIGMATISM - this common condition occurs when the front
surface of the eye (cornea) is not round in shape, but instead is
shaped irregular or warped similar to a football. This results in
vision being blurred at all distances. Symptoms include eyestrain,
headaches, blurred vision, double vision, and haloes around lights.
Glasses can be worn full time or worn mostly during highly concentrated
*PRESBYOPIA - this vision condition results when the focusing
lens of the eye loses its flexibility and therefore the eye gradually
loses its ability to focus clearly on near objects. This is a natural
part of aging and usually occurs when a person reaches the age of
early to mid-forties. Some signs and symptoms of presbyopia include
the tendency to hold reading material at arms length, blurred vision
at a normal reading distance, eyestrain and headaches when attempting
to do close work. Usually bifocals or reading glasses are prescribed.
Reading glasses can only be worn for near work, while bifocals can
be worn all the time, part-time or mainly for near work.
*AMBLYOPIA (LAZY EYE) - this is a condition of blurred vision
resulting from a lack of development of vision in usually one eye
that is unrelated to any eye health problems. Vision is not fully
restored with corrective lenses. Amblyopia is usually caused by
a failure to use both eyes together, either due to one eye not being
aligned straight or when there is a large difference in the prescription
between the two eyes. This causes the brain to ignore one eye in
favor of the other, resulting in poor development of vision in the
eye not being used. This abnormality usually occurs before the age
of five or six. Treatment of amblyopia includes glasses, contact
lenses and vision therapy. In some cases, placing a patch over the
good eye to force the use of the weakened eye can help strengthen
and improve vision in the amblyopic eye. Surgery may be indicated
to help straighten an amblyopic eye that is misaligned. In a lot
of cases the amblyopic eye will never see as clearly as the other
*STRABISMUS (CROSSED-EYES) - this is a condition in which
the eyes are not properly aligned with each other. For a variety
of reasons, one or both eyes turn in, out, up or down. Children
under the age of six are the ones most affected by strabismus, but
it often first appears between birth and age 21 months. Strabismus
can lead to amblyopia (lazy eye) because the brain will ignore one
eye to prevent double vision due to both eyes not focusing on the
same object. Treatment for strabismus can include glasses (regular
or bifocal), prisms, vision therapy and sometimes surgery. Treatment
success depends on how early the condition is detected and treated.