Asthenopia is the medical term used to
refer to the condition more commonly known as eyestrain.
Eyestrain is a term used to refer to the sense of fatigue
that can result from prolonged "close work" (intense visual
focus on text or objects within 1 foot or 30cm of the eyes, or slightly
further away in the cases of certain larger objects). This is generally
worse in cases of:
- insufficient illumination,
- the person already being tired (such as if working late at night),
and/or
- the person has an uncorrected error of refraction or an imbalance
of the muscles that move and control movement of the eyes.
Eyestrain generally occurs when the muscles that support
and operate the eye have been over-used (at that particular point in time,
e.g. work session) and are therefore extremely tired. This condition concerns
the eyes but, in general, when any muscle is held in one position
for too long, the muscle will start to strain. In the case of the eye
muscles, over-tired muscles may tighten - resulting in the eyes beginning
to hurt and to feel irritated, dry and uncomfortable. Further symptoms
of eyestrain can include the sensation of "buring eyes", blurring
vision, and headaches.
Many online articles about eyestrain focus on this condition
occuring as a result of long work at computer screens. This is, of course,
a common modern scenario. However, the same effects can result from excessive
viewing of (especially a close) television, or even from more traditional
forms of close-work such as needlework (e.g. tapestry), drawing, writing,
examination of specimens (e.g. using microscopes) and so on.
More about Ophthalmology: This section includes short definitions
of many diseases, disorders, and conditions of the eyes and visual system.
For definitions of other terms in this category, choose from the list
to the left (but note that this is not a complete/exhaustive list).
Other related pages include the diagram
of the eye, and definitions
of parts of the eye, a description
of the human retina, and definitions
of parts of the retina, and the section of short definitions
of clinical and surgical procedures re. eyes and human visual system.
For further information see also our section of Books
about Ophthalmology. |
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This Section
is about
Diseases
and Disorders of the Eyes and Visual System.
To read about other diseases, disorders, or conditions of the eye and
human visual system, use the links on the left-side of this page.
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