Andrew A. Dahl, MD, is a board-certified ophthalmologist. Dr. Dahl's educational background includes a BA with Honors and Distinction from Wesleyan University, Middletown, CT, and an MD from Cornell University, where he was selected for Alpha Omega Alpha, the national medical honor society. He had an internal medical internship at the New York Hospital/Cornell Medical Center.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
The term eye strain is frequently used by people to describe a group of
symptoms which are related to use of the eyes. Eye strain is a symptom, not an
eye disease. Eye strain occurs when your eyes get tired from intense use, such as
driving a car for extended periods, reading, or working at the computer. If you
have any eye discomfort caused by looking at something for a long time, you can
call it eye strain.
Although eye strain can be annoying, it usually is not serious and goes away
once you rest your eyes. In some cases, signs and symptoms of eye strain are a
sign of an underlying eye condition that needs treatment. Although you may not
be able to change the nature of your job or all the factors that can cause
eye strain, you can take steps to reduce eye strain.
What causes eye strain?
The medical term for eye strain is asthenopia. The symptoms of ocular
fatigue, tired eyes, blurring, headaches, and occasionally doubling of the
vision are brought on by concentrated use of the eyes for visual tasks. Some
people, while concentrating on a visually intense task such as reading fine
print, using the computer for hours at a time, or trying to see in the dark,
unconsciously clench the muscles of their eyelids, face, temples, and jaws and
develop discomfort or pain from use of those muscles. This may lead to a vicious
cycle of tensing those muscles further and causing more distress. Other people
attempting to do similar visual tasks may have no symptoms at all.
Common precipitating factors for the onset of eye strain include extended use
of a computer or video monitor, straining to see in very dim light, and exposure
to extreme brightness or glare. Many people will blink less than normal when
performing extended visual tasks. This decreased blinking may lead to dryness of
the ocular surface and symptoms of dry eyes.
Refractive errors (a need for glasses for distance or near vision, or both)
may produce the symptoms of eye strain. People who require glasses, however,
often do not develop asthenopia even when they fail to wear their glasses.
The inability to make both eyes work together in a binocular fashion may also
generate the symptoms of eye strain. However, most individuals who have limited
or no binocular vision have no such symptoms.
In people who already have headaches or blurring of vision due to eye strain,
symptoms may be worsened by an underlying eye problem such as an eye muscle
imbalance or a need for glasses for the correction of myopia, hyperopia, or
astigmatism. In those who already have eye strain, not getting enough sleep,
certain medications, being under stress, or being fatigued can also make those
symptoms worse.
Headaches can be divided into two categories: primary headaches and secondary headaches. Migraine headaches, tension headaches, and cluster headaches are considered primary headaches. Secondary headaches are caused by disease. Headache symptoms vary with the headache type. Over-the-counter pain relievers provide short-term relief for most headaches.
Stress occurs when forces from the outside world impinge on the individual. Stress is a normal part of life. However, over-stress, can be harmful. There is now speculation, as well as some evidence, that points to the abnormal stress responses as being involved in causing various diseases or conditions.
Dry eyes are caused by an imbalance in the tear-flow system of the eye, but also can be caused by the drying out of the tear film. This can be due to dry air created by air conditioning, heat, or other environmental conditions.
A number of vital tasks carried out during sleep help maintain good health and enable people to function at their best. Sleep needs vary from individual to individual and change throughout your life. Not getting enough sleep can hurt memory performance, health, and your mood.
Many common eye disorders resolve without treatment and some may be managed with over-the-counter (OTC) products. It's important to visit a physician or ophthalmologist is the problem involves the eyeball itself or the condition hasn't improved after 72 hours of use of an eye-care OTC product.
Astigmatism is a common eye condition that's easily corrected by eyeglasses, contact lenses, or surgery. Symptoms of astigmatism are headaches, fatigue, eyestrain and blurred vision.
Myopia, or nearsightedness, makes it difficult to focus on objects that are far away. The condition runs in families and occurs because light focuses in front of the retina, instead of directly on it. Headaches, eye strain, and fatigue are symptoms of myopia. The condition is diagnosed by having an eye exam and can be treated by wearing glasses or contact lenses or by having refractive surgery.
Nonprescription eyeglasses are available over the counter (OTC) and are typically used by people who can no longer read fine print. OTC trifocals are helpful for those who require multiple distances or focal lengths for near and intermediate tasks. OTC sunglasses should offer 100% protection from the sun's UVA and UVB rays. OTC magnifying glasses are useful for viewing tiny objects or fine print.
Farsightedness makes it difficult to focus on objects that are close up. The condition runs in families and occurs because light focuses behind the retina, instead of directly on it. Headaches, eye strain, and fatigue are symptoms of farsightedness. The condition is diagnosed by having an eye exam and can be treated by wearing glasses or contact lenses or by having refractive surgery.
Astigmatism is a common eye condition that's easily corrected by
eyeglasses,
contact lenses or surgery.
Astigmatism is characterized by an irregular curvature of the cornea. This
is one type of refractive error. Astigmatism occurs in
nearly everybody to some degree. For significant curvature, treatment is
required.
A person's eye is naturally spherical in shape. Under normal circumstances,
when light enters the eye, it refracts evenly, creating a clear view of the
object. However, the eye of a person with astigmatism is shaped more like a
football or the back of a spoon. For this person, when light enters the eye it
is refracted more in one direction than the other, allowing only part of the
object to be in focus at one time. Objects at any distance can appear
blurry and
wavy.