Asthenopia is becoming a public health problem due to lifestyle changes and increasing usage of computers in colleges and various industries [1] [2]. The term asthenopia includes several different clinical manifestations arising secondary to the excessive use of eyesight [3] [4] [5]. The symptoms are found to have a female preponderance with high school students presenting with ocular symptoms more frequently compared to primary school children due to their increasing use of computers [5]. Specific ocular clinical manifestations are photophobia, blurring of vision, eye redness, diplopia, itching of eyes, excessive tearing, dry eyes, and foreign body sensation [3] [6]. Other symptoms include headaches, eye soreness, fatigue, and irritation [3] [4] [5] [6]. Severe symptoms of asthenopia have been reported to accelerate age-related ocular diseases [7], reduce productivity and quality of life [8] [9]. Factors postulated to have a strong association with asthenopia include computer usage, psychosocial status, environment conditions, posture, and diet.

Asthenopia is classified as either internal or external [3].

• Internal or accommodative asthenopia presents with eye strain and pain inside the eyes and is due to ciliary muscle overuse [3] [6]. It can be caused by uncorrected refractive errors, convergence and accommodation insufficiency, or decompensated heterophoria [6] [10].
• External or muscular asthenopia is due to extraocular muscle weakness and presents with dryness and irritation of the eyes. It is associated with nerve palsies, strabismus, glare from lights, flickering stimuli from computer displays, and dry eyes [3].

• Contusion

  We report a 22-year-old female with a history of contusion of bilateral occipital lobes at the age of 1 year. Magnetic resonance imaging confirmed severe lesion in bilateral striate cortices which should have resulted in cortical blindness. [ncbi.nlm.nih.gov]

  […] muscular asthenopia and eccentric ablation. ( 11780199 ) Wu G....Yao Z. 2001 37 An unusual cause of asthenopia: "pseudo-accommodative insufficiency" associated with a high AC:A ratio. ( 11186867 ) Houston C.A....Weir C.R. 2000 38 Bilateral striate cortex contusion [malacards.org]

• Blurred Vision

  Furthermore, significant correlations were found between total nearwork time and blurred vision, and blurred vision and reduced accommodative facility. [ncbi.nlm.nih.gov]

  Asthenopia encompasses all of the disorders and problems that arise in relation to looking at objects up close such as eye discomfort, blurred vision, sporadic double vision, premature tiredness, the inability to maintain a consistently clear image from [eyecos.eu]

  The symptoms of eye strain are varied and might include: Headaches Blurred vision Light sensitivity Red, watery eyes Painful or sore eyes Dry eyes Tired eyes Back and neck aches Muscle spasms Most, if not all, symptoms of eye strain are easily remedied [specsavers.co.uk]

• Headache

  Symptoms include pain in or around the eyes, headache, dimness of vision, dizziness, and slight nausea. as·the·no·pi·a ( as'thĕ-nō'pē-ă ) Subjective symptoms of ocular fatigue, discomfort, lacrimation, and headaches arising from use of the eyes. [medical-dictionary.thefreedictionary.com]

  After watching S3D TV for 20 min, a survey of subjective symptoms was conducted with a questionnaire to evaluate the degree of S3D perception and asthenopic symptoms such as headache, dizziness and ocular fatigue while watching 3D TV. [ncbi.nlm.nih.gov]

  Asthenopia Definition Eyestrain Subjective symptoms of ocular fatigue, discomfort, lacrimation, and headaches arising from the use of eyes. Weakness or tiring of eyes accompanied by pain, headache, and dimness of vision. [eyewiki.aao.org]

  At times, the intensity of the headaches associated with asthenopia can be considerable and may even result in migraines with nausea and vomiting. B) Myopia. [eyecos.eu]

  It is accompanied by Headache and Weak Eye Sight. [herbpathy.com]

Clinical presentation of asthenopia is similar to various other ocular disorders posing clinicians and optometrists with diagnostic challenges [3] [10]. Evaluation of patient's symptoms along with clinical measures helps to diagnose the condition and plan further management. The workup should start with a detailed history to elicit eyestrain at the college or work, refractive errors, use of spectacles or contact lenses, and previous laser surgery to correct refractive errors. An ophthalmological examination is essential to evaluate tear film, corneal opacities, and refraction. Visual acuity test, cycloplegic refraction test, and fundoscopy must be performed in all cases of asthenopia. The cover or patch test helps to confirm the diagnosis of asthenopia and differentiate between the two types of asthenopia. Persistence of symptoms after patching one eye for several hours indicates accommodative stress while relief of symptoms after resting one eye indicates muscular incompetence. Tests to differentiate accommodative insufficiency from ocular myasthenia gravis such as the Tensilon test, acetylcholine receptor antibody titers, and single fiber electromyography (EMG) testing can also be performed.

Laboratory and radiological studies are usually not indicated during the workup.

Abstract The aim of this study was to describe the orthoptic and ophthalmological findings in schoolchildren with asthenopia, to correlate them with asthenopic symptoms and to evaluate the effect of treatment. [ncbi.nlm.nih.gov]

Fat and Blood An Essay on the Treatment of Certain Forms of Neurasthenia and Hysteria [wordnik.com]

All four groups underwent an eight week treatment. Group 2 and 3 received optometric/orthoptic treatment of their asthenopia. Group 1 and 4 received placebo treatment, i.e. a pair of plano or 0.25D glasses. [iovs.arvojournals.org]

Cooper, J, Duckman, R 1978 Convergence Insufficiency: Incidence, diagnosis, and treatment Am J Optom Assoc 49 673 9 Google Scholar 21. [link.springer.com]

What is the prognosis of eye strain? The symptom of eye strain does not result in any damage to the eyes. Therefore, the prognosis is excellent. Relief of eye strain symptoms will usually occur using the above techniques. [medicinenet.com]

Etiology and pathogenesis ASTHENOPIA MUSCLE (ASTHENOPIA MUSCULARIS) Etiology. Dissociation between accommodation and convergence in myopia of medium degree (especially in the range of 3.0 - 6.0 D). The pathogenesis. [lecheniebolezni.com]

Etiology Accommodative asthenopia: strain of ciliary muscle and refractive error. Photogenous asthenopia: excessive or improper illumination. [eyewiki.aao.org]

[…] may be referred to asthenopia, a visual disorder that reveals itself through eyestrain, fatigue, pain in or around the eyes, and blurred vision. 5 Aside from the association with jobs requiring intensive utilization of visual display terminals, its etiology [nature.com]

Importantly, the underlying etiology of eyestrain must be better understood. [reviewofoptometry.com]

This is frequently caused by a lack of appropriate cortical output that is necessary for accurate accommodative and fusional vergence system responses, and for the demands of the task. 1 As seen in figure 2, there are a number of etiologies for asthenopia [mivision.com.au]

AIMS: To study the prevalence of asthenopia among computer operators and its association with various epidemiological factors. [ncbi.nlm.nih.gov]

Manuel AP Vilela, 1,2 Victor D Castagno, 2,3 Rodrigo D Meucci, 3,4 Anaclaudia G Fassa 3,4 1 Postdoctoral Program in Epidemiology, 2 Department of Specialized Medicine – Ophthalmology, 3 Doctoral Program in Epidemiology, 4 Department of Social Medicine [dovepress.com]

BACKGROUND: The objective of this study was to experimentally investigate whether a new visual intervention with optical and binocular vergence demands prevents accommodative insufficiency and asthenopia after sustained periods of visual task. [ncbi.nlm.nih.gov]

In the same way as a droplet of oil dropped into a cup, the oil layer forms a thin film to prevent heating of tears. The mucin layer fulfills the role of glue that adheres to the surface of the eye to prevent tears from running out of the eye. [seiko-opt.co.jp]

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