Description, Causes and Risk Factors:
Asthenopia is an ophthalmological disease and condition that manifests itself through nonspecific symptoms such as fatigue, pain in or around the eyes, blurred vision, headache and occasional double vision. Symptoms often occur after reading, computer work, or other close activities that involve tedious visual tasks.
When concentrating on a visually intense task, such as continuously focusing on a book or computer monitor, the ciliary muscle tightens. This can cause the eyes to get irritated and uncomfortable. Giving the eyes a chance to focus on a distant object at least once an hour usually alleviates the problem.
A CRT computer monitor with a low refresh rate (<70Hz) or a CRT television can cause similar problems because the image has a visible flicker. Aging CRTs also often go slightly out of focus, and this can cause eye strain. LCDs do not go out of focus and are less susceptible to visible flicker.
A page or photograph with the same image twice slightly displaced (from a printing mishap, or a camera moving during the shot as in this image) can cause eye strain by the brain misinterpreting the image fault as diplopia and trying in vain to adjust the sideways movements of the two eyeballs to fuse the two images into one.
Sometimes, asthenopia can be due to specific visual problems, for example, uncorrected refraction errors or binocular vision problems such as accommodative insufficiency or heterophoria. It is often caused by the viewing of monitors such as those of computers or phones.
Muscular asthenopia can be caused by overexertion convergence. Unpleasant effects disappear if you close one eye, that is, off convergence. Exotropia may occur.
Mixed asthenopia, usually characterized combined picture and the accommodative muscle of eye fatigue. The reasons for its the same as that of each of them. Treatment combination.
Neurogenic asthenopia often seen as a manifestation of the general neurasthenia and hysteria. Therefore, it can occur when the part of the vision there are no prerequisites for the emergence of asthenopia.
Accommodative asthenopia is the most common form. It can be due to presbyopia, weakened as a result of accommodation of common diseases, spasm of accommodation. Since accommodation is more farsighted people, especially during visual work at close range, the farsighted people of accommodative asthenopia more common.
Twenty subjects with good vision performed eight reading tasks in random order during different conditions. Each condition used different stimuli to induce asthenopia. The eight conditions were mixed astigmatism, close viewing distance, upward gaze, dry eyes, lens flipper, small font, glare, and flickering light. Subjects were asked to read until attaining a level of discomfort self-defined as "barely tolerable." After each task, subjects rated the magnitude of several symptom descriptors (burning, ache, strain, irritation, tearing, blurred vision, double vision, dryness, and headache) and their location. Analysis of variance with repeated measures was used to determine that all of the individual symptom sensation measures (except blur) were significantly related (p values ranged from 0.003 to <0.0001) to the inducing condition. Principal factor analysis with orthogonal varimax rotation was used to test symptom by condition relationships and determined two latent factors, designated external and internal symptom factors (ESF and ISF), that related symptoms to inducing condition. The ESF pattern comprises burning, irritation, tearing, and dryness located in the front and bottom of the eye. ESF is caused by holding the eyelid open, glare, up gaze, small font, and flickering. ESF seems highly related to dry-eye symptoms. The ISF pattern comprises ache, strain, and headache located behind the eyes. ISF is caused by the close viewing distance, lens flipper, and mixed astigmatism conditions and is likely related to accommodative and vergence stress.
Preventive Measures: Taking eye breaks for 5 minutes every hour can really improve the amount of strain you put on your eyes. Simply closing your eyes for a few moments can also do wonders. Try standing up, moving around or taking a short walk to help gain concentration back. Regular eye exercises that involve focusing on different distances can help prevent future straining. Blink often. Blinking refreshes and replenishes your eyes naturally. If you are having trouble with blinking due to the dryness of your eyes, try using artificial tears without preservatives. If the eye drops do contain preservatives, do not use them more than four times per day.
General symptoms may include:
Pain around the eyes.
Diagnosis may include: Detail questionnaire which may include history of use of glasses, occupation history, duration of work, illumination in the work place, etc.
Corneal clarity: Any corneal opacity can increase the glare.
From computer monitors.
Refraction: It is important to do a cycloplegic refraction in allthese cases.
Check lids, tear film.
Change - The first thing you can do is change your environment and/or work habits. By doing this you can help yourself relieve the pain without spending money on treatment. If you are in a dry environment, try using a humidifier. If you work on the computer try taking more “eye breaks.”
Treat Underlying Cause - If there's an underlying cause such as refractive error, get treatment for it. Talk with your Ophthalmologist (Eye Care Professional) as soon as possible to discuss options for treatment.
Eye Exams - You should be getting your eyes checked at least once a year, especially as you grow older. Routine eye exams give you the opportunity to discuss issues you may be having with your eye care professional, as well as catch problems while they are in the earlier stages.
Better Rx - If you do spend a lot of time sitting in front of a computer or reading, maybe you need prescription glasses solely for those activities. These are not eyewear for constant usage, only during these activities.
There are a few herbal topical drops that are supposed to be helpful in decreasing asthenopia. They contain extracts of Tulasi, Pudina, Bhringraj, Dhatriphala, etc.
NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.
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