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].

• Fatigue

  The Exo group reported more eye fatigue (p < 0.001, Kruskal-Wallis test) than the Eso and the control group. [ncbi.nlm.nih.gov]

  See convergence excess ; convergence insufficiency ; divergence insufficiency ; visual fatigue ; ocular headache. [medical-dictionary.thefreedictionary.com]

  It is caused by long hours of near work leading to eye fatigue. Asthenopia can be of either the accommodative type or the muscular type and the two types can be differentiated with a patch test. [symptoma.com]

  Another very effective alternative to prevent visual fatigue is perform relaxation eye exercises that help combat eye fatigue and, therefore, prevent asthenopia. [areaoftalmologica.com]

• Pain

  Group 1: with neck-shoulder pain but without asthenopia. Group 2: with neck-shoulder pain and asthenopia. Group 3: with asthenopia but without neck-shoulder pain. Group 4: without neck-shoulder pain and without asthenopia. [iovs.arvojournals.org]

  (pain behind the eyes), etc. [eyecos.eu]

  […] asthenopia [ as″thĕ-no´pe-ah ] weakness or easy fatigue of the eye, with pain in the eyes, headache, and dimness of vision. adj., adj asthenop´ic. accommodative asthenopia asthenopia due to strain of the ciliary muscle. muscular asthenopia asthenopia [medical-dictionary.thefreedictionary.com]

  Although often painful, eye strain doesn't lead to permanent eye damage. [specsavers.co.uk]

• Inflammation

  Fuji Chemical also holds seven patents for astaxanthin in the human application areas of inflammation, muscle endurance, immune system, dyspepsia, mastitis, fertility and H-pylori, as well as numerous pending patents. [newhope.com]

  […] either when the accommodation amplitude is low or hypermetropia is uncorrected ( accommodative asthenopia ), aniseikonia ( aniseikonic a .), astigmatism ( astigmatic a .), pain in the eye ( asthenopia dolens ), heterophoria ( heterophoric a .), ocular inflammation [medical-dictionary.thefreedictionary.com]

  In the kindergarten and primary school the ASTENOPIC complaints due to hipermetropia, minor astigmatism and convergent deficit as well as chronic inflammation of the anterior segment eyelids and anexus, can be related with poor school performance more [ncbi.nlm.nih.gov]

  Effects of astaxanthin on lipopolysaccharide-induced inflammation in vitro and in vivo. Invest. Ophthal. Vis. Sci., 44(6):2694-2701. [fujichemical.co.jp]

  […] blefaritis, fotofobia, agudeza visual disminuida, astenopia, hinchazón ocular, aumento del lagrimeo, eritema del párpado, crecimiento de pestañas, alergia ocular, edema conjuntival, edema del párpado. keratitis, iritis, conjunctivitis, anterior chamber inflammation [context.reverso.net]

• Asymptomatic

  Abstract To study asthenopia, we compared the dark focus of accommodation of 54 symptomatic and 56 asymptomatic control subjects. The two groups were matched for age and cycloplegic refractive error. [ncbi.nlm.nih.gov]

  The clinician should inquire about any avoidance behavior in patients who are asymptomatic despite clinical findings consistent with convergence insufficiency. [13, 14] The most common symptoms associated with convergence insufficiency include asthenopia [emedicine.medscape.com]

  It has been shown that by increasing the treatment time even beyond 12 weeks the proportion of patients being asymptomatic increases. 16 Asthenopic symptoms are a common complaint not only in working-age people 1 but also in schoolchildren 6 and convergence [journalofoptometry.org]

• Fishing

  These results suggest that dietary supplementation with the combination of omega-3 fatty acid-rich fish oil, bilberry extract, and lutein may safely improve subjective symptoms of asthenopia and mental fatigue in humans. [ncbi.nlm.nih.gov]

  […] color preference in asthenopia. ( 22733104 ) Drew S.A....Chase C. 2012 20 Asthenopia (eyestrain) in working children of gem-polishing industries. ( 20940266 ) Tiwari R.R....Parikh J.R. 2011 21 Effects of dietary supplementation with a combination of fish [malacards.org]

• Hypertension

  […] fluorescein dye dilution test Soft or Hard contact lens use 3 or more days a week History of oral intake of health supplement designed to improve asthenopia within 4 weeks before participating this study Pregnant woman Systemic disease Uncontrolled hypertension [clinicaltrials.gov]

  Out of all respondents, only 1 (0.2%) was diabetic and 4 (1.0%) were hypertensive. [ncbi.nlm.nih.gov]

• Pruritus

  The two groups displayed similar symptomatology at the beginning: bulbar hyperemia 60%, tarsal hyperemia 50%, ocular irritation 40%, pruritus 38%, frontal migraine 13%, tears 13%, asthenopia while reading 21% among others. [context.reverso.net]

• Muscle Spasm

  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]

  spasms Most, if not all, symptoms of eye strain are easily remedied, however if these symptoms become persistent or worsen it is advisable that you visit your optometrist as soon as possible. [specsavers.co.nz]

  If the conditions remain adverse, the oblique muscles can spasm. Once those muscles spasm, a different model for near focusing seems to take place. [oapublishinglondon.com]

• 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]

  […] asthenopia and eccentric ablation. ( 11780199 ) Wu G....Yao Z. 2001 37 An unusual cause of asthenopia: &quot;pseudo-accommodative insufficiency&quot; 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]

  People with hyperopia can experience blurred vision, asthenopia, accommodative disfunction, binocular disfunction, amblyopia, and strabismus, another condition that frequently causes blurry near vision. [en.bab.la]

  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]

  Although often painful, eye strain does not lead to permanent damage to the eye.The symptoms of eye strain are many and varied and may include; Headaches Blurred vision Light sensitivity Red, watery eyes Painful or sore eyes Dry eyes Tired eyes Back and [specsavers.co.nz]

• Dry Eyes

  Dry eye is one cause of asthenopia One of the causes of asthenopia is so-called "dry eye. In technical jargon, dry eye is "damage to the eyes caused by abnormalities in lachrymal secretion." [seikoeyewear.com]

  Specific ocular clinical manifestations are photophobia, blurring of vision, eye redness, diplopia, itching of eyes, excessive tearing, dry eyes, and foreign body sensation. Other symptoms include headaches, eye soreness, fatigue, and irritation. [symptoma.com]

  One of the causes of asthenopia is so-called "dry eye." In technical jargon, dry eye is "damage to the eyes caused by abnormalities in lachrymal secretion." [seiko-opt.co.jp]

  […] very dim light Having an underlying eye problem, such as dry eyes or uncorrected vision (refractive error) Being stressed or fatigued Being exposed to dry moving air from a fan, heating or air-conditioning system Computer and digital device use Extended [mayoclinic.com]

• Strabismus

  None of these participants had previously noticed symptoms of strabismus. Only the presence of strabismus was significantly different between the groups (P = .008). [ncbi.nlm.nih.gov]

  In the absence of ghosting to distinguish it from accomodative asthenopia should do a test on latent strabismus (with approximations of the object one eye given). [lecheniebolezni.com]

• Eye Pain

  VDT workers who complained of worsened vision, redness of the eyes, eye pain, and diplopia during work were found to show more significant changes in the psycho-physiological indicators objectively reflecting strain of the vision analyzer. [ncbi.nlm.nih.gov]

  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]

• Diplopia

  Se a convergência for insuficiente ou inadequada, mesmo com acuidade e acomodação normais, tem-se um quadro de astenopia com diplopia. [en.bab.la]

  VDT workers who complained of worsened vision, redness of the eyes, eye pain, and diplopia during work were found to show more significant changes in the psycho-physiological indicators objectively reflecting strain of the vision analyzer. [ncbi.nlm.nih.gov]

  Diplopia The diplopia that manifests in patients with convergence insufficiency may present as two separate or overlapping images (a "ghost" image). [emedicine.medscape.com]

  Specific ocular clinical manifestations are photophobia, blurring of vision, eye redness, diplopia, itching of eyes, excessive tearing, dry eyes, and foreign body sensation. Other symptoms include headaches, eye soreness, fatigue, and irritation. [symptoma.com]

• 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]

  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]

  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]

  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]

• Irritability

  Other symptoms include headaches, eye soreness, fatigue, and irritation. Severe symptoms of asthenopia have been reported to accelerate age-related ocular diseases, reduce productivity and quality of life. [symptoma.com]

  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. [journals.lww.com]

  Eyestrain included symptoms like itching, burning, or irritated eyes; tired or heavy eyes; difficulty seeing clearly (including blurred or double vision); and headache. [ncbi.nlm.nih.gov]

  There are many causes for eye strain, including incorrect glasses, motility problems (the eyes out of alignment), or even from surface irritation such as dry eye . [timroot.com]

  Lack of sleep may lead to repeated eye irritation. How Can You Prevent Eye Fatigue? Make some simple changes to: Continued Your computer screen: Place it 20-26 inches away from your eyes and a little below eye level. [m.webmd.com]

• Frontal Headache

  Symptoms include pain in the eyeball, frontal headache, blurring of vision, and smarting and watering of the eye. These are usually worse toward evening and are aggravated by close work such as reading. [britannica.com]

  Case 2 A 20 year old man was referred complaining of blurred vision for near work, associated with frontal headaches. His visual acuities were 6/5, N5 in each eye. Cycloplegic refraction showed no significant refractive error. [bjo.bmj.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.

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]

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]

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

Treat the underlying cause: If there’s an underlying cause such as refractive error, get treatment for it. Talk with your eye-care professional as soon as possible to discuss options for treatment. [eyehealthweb.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]

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

[…] 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]

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]

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]

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

Another very effective alternative to prevent visual fatigue is perform relaxation eye exercises that help combat eye fatigue and, therefore, prevent asthenopia. [areaoftalmologica.com]

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]

1. Bhanderi DJ, Choudhary S, Doshi VG. A community-based study of asthenopia in computer operators. Indian J Ophthalmol. 2008;56(1):51–55.
2. Thorud HM, Helland M, Aarås A, et al. Eye-related pain induced by visually demanding computer work. Optom Vis Sci. 2012; 89(4): E452–E464.
3. Sheedy JE. The physiology of eyestrain. J Mod Optics. 2007;54: 1333–1341.
4. Grosvenor T. Primary care optometry. 5th ed. Philadelphia: Butterworth Heinemann Elsevier; 2007.
5. Feldman F, Cooper J. Assessing the reliability and validity of an asthenopia questionnaire. American Optometric Association. http://avehjournal.org/index.php/aveh/article/viewFile/293/pdf_1. Accessed 08 Feb 2017.
6. Sheedy JE, Hayes J, Engle J. Is all asthenopia the same? Optom Vis Sci. 2003;80:732–739.
7. Pointer JS, Gilmartin B. Clinical characteristics of unilateral myopic anisometropia in a juvenile optometric practice population. Ophthalmic Physiol Opt. 2004;24(5):458–463.
8. Ip JM, Robaei D, Rochtchina E, Mitchell P. Prevalence of eye disorders in young children with eyestrain complaints. Am J Ophthal. 2006;142:495–497.
9. Alexander JA, Joyes D, Liew C, Omrod M, Wong A. A survey of cases in Sydney optometric practices: Age and sex distributions; symptoms and reasons for consultation. Aust J Optom. 1985;68:133–138.

10. Scheiman M, Wick B. Clinical management of binocular vision: Heterophoric, accommodative and eye movement disorders. 3rd ed. Philadelphia, PA: JB Lippincott; 2008.