Eye strain, also known as asthenopia (from Greek ''a-sthen-opia'', grc, ἀσθενωπία, ), is a common
eye condition that manifests through
non-specific symptom
Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showin ...
s such as fatigue, pain in or around the eyes,
blurred vision,
headache
Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches.
Headaches can occur as a result ...
, and occasional
double vision
Diplopia is the simultaneous perception of two images of a single object that may be displaced horizontally or vertically in relation to each other. Also called double vision, it is a loss of visual focus under regular conditions, and is often v ...
. Symptoms often occur after long-term use of computers, digital devices, reading or other activities that involve extended visual tasks which are broadly classified into external and internal symptom factors.
When concentrating on a visually intense task, such as continuously focusing on a book or computer monitor, the
ciliary muscles
The ciliary muscle is an intrinsic muscle of the eye formed as a ring of smooth muscleSchachar, Ronald A. (2012). "Anatomy and Physiology." (Chapter 4) . in the eye's middle layer, uvea (vascular layer). It controls accommodation for viewing o ...
and the extraocular muscles are strained. This causes discomfort, soreness or pain on the eyeballs. Closing the eyes for ten minutes and relaxing the muscles of the face and neck at least once an hour usually relieves the problem.
A page or photograph with the same image twice, but slightly displaced (from a printing mishap, a camera moving during the shot, etc.) can cause eye strain due to the brain misinterpreting the image fault as
diplopia
Diplopia is the simultaneous perception of two images of a single object that may be displaced horizontally or vertically in relation to each other. Also called double vision, it is a loss of visual focus under regular conditions, and is often v ...
and trying in vain to adjust the sideways movements of the two eyeballs to fuse the two images into one.
Eye strain can also happen when viewing a blurred image (including images deliberately partly blurred for censorship), due to the ciliary muscle tightening trying in vain to focus the blurring out.
Symptoms
*
blurred vision
* sore, tired, burning, or itching eyes
* difficulty concentrating
*
dry eyes
Dry eye syndrome (DES), also known as keratoconjunctivitis sicca (KCS), is the condition of having dry eyes. Other associated symptoms include irritation, redness, discharge, and easily fatigued eyes. Blurred vision may also occur. Symptoms rang ...
or watery eyes
* eye discomfort
* headaches
* irritated or burning eyes
* sensitivity to bright lights
* tired eyes
* sore eyes
Therapy
Known methods of relieving strain of the ocular muscles are taking periodic breaks by closing the eyes, obtaining good sleep, and proper nutrition.
See also
*
Astigmatism
Astigmatism is a type of refractive error due to rotational asymmetry in the eye's refractive power. This results in distorted or blurred vision at any distance. Other symptoms can include eyestrain, headaches, and trouble driving at nig ...
*
Computer vision syndrome
Computer vision syndrome (CVS) is a condition resulting from focusing the eyes on a computer or other display device for protracted, uninterrupted periods of time and the eye's muscles being unable to recover from the constant tension required to ...
*
Eye examination
An eye examination is a series of tests performed to assess vision and ability to focus on and discern objects. It also includes other tests and examinations pertaining to the eyes. Eye examinations are primarily performed by an optometrist, op ...
*
Ocular neurosis Ocular neurosis is the usual cause of eye strain headache
Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in thos ...
*
Photophobia
Photophobia is a medical symptom of abnormal intolerance to visual perception of light. As a medical symptom photophobia is not a morbid fear or phobia, but an experience of discomfort or pain to the eyes due to light exposure or by presence of ...
*
Vision therapy
Vision therapy (VT), or behavioral optometry, is an umbrella term for alternative medicine treatments using eye exercises, based around the pseudoscientific claim that vision problems are the true underlying cause of learning disabilities, parti ...
*
Visual looming syndrome
''Looming'' is a term found in the study of perception, as it relates directly to psychology. Looming occurs when an object begins moving closer to the eye. As the resulting image becomes increasingly larger on the perceiver's retina, i.e., when ...
References
External links
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Visual disturbances and blindness