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].

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.

Treatment for asthenopia focuses on alleviating symptoms and addressing underlying causes. Recommendations may include taking regular breaks during visual tasks, using proper lighting, and ensuring optimal screen settings. Corrective lenses or vision therapy may be prescribed if refractive errors or eye alignment issues are present. Artificial tears can help relieve dryness.

The prognosis for asthenopia is generally favorable, especially when underlying causes are identified and managed. Most patients experience significant relief with appropriate interventions and lifestyle modifications. However, symptoms may recur if preventive measures are not maintained.

Asthenopia can result from various factors, including prolonged visual tasks, poor lighting, incorrect screen settings, and uncorrected vision problems. Psychological stress and fatigue can also contribute to the development of symptoms. In some cases, underlying eye conditions, such as dry eye syndrome or binocular vision disorders, may play a role.

Asthenopia is a common condition affecting individuals of all ages, particularly those who engage in extensive near work, such as students and office workers. The prevalence has increased with the widespread use of digital devices, leading to what is often referred to as "computer vision syndrome."

The pathophysiology of asthenopia involves a combination of visual and muscular fatigue. Prolonged focus on near objects requires sustained contraction of the eye muscles, leading to discomfort. Additionally, reduced blink rates during screen use can cause dryness and irritation, further contributing to symptoms.

Preventing asthenopia involves adopting healthy visual habits. The 20-20-20 rule is a simple strategy: every 20 minutes, take a 20-second break to look at something 20 feet away. Ensuring proper lighting, maintaining an ergonomic workspace, and using appropriate corrective lenses can also help prevent symptoms.

Asthenopia, or eye strain, is a common condition resulting from prolonged visual tasks. It presents with symptoms like eye discomfort, headaches, and blurred vision. Diagnosis involves a comprehensive eye examination, and treatment focuses on lifestyle modifications and addressing underlying causes. With proper management, the prognosis is generally good.

For patients experiencing eye strain, it's important to be mindful of visual habits. Taking regular breaks, ensuring good lighting, and using screens at a comfortable distance can help alleviate symptoms. If discomfort persists, consulting an eye care professional is advisable to rule out underlying issues and receive personalized recommendations.

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.