Computer vision syndrome

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Computer vision syndrome (CVS) is a condition resulting from focusing the eyes on a computer or other display device for protracted, uninterrupted periods of time and the eye's muscles being unable to recover from the constant tension required to maintain focus on a close object.

Contents

Symptoms

Some symptoms of CVS include headaches, blurred vision, neck pain, fatigue, eye strain, [1] dry eyes, irritated eyes, double vision, vertigo/dizziness, polyopia, and difficulty refocusing the eyes. These symptoms can be further aggravated by improper lighting conditions (i.e. glare, [2] [3] strong blue-spectrum backlights,[ citation needed ] or bright overhead lighting) or air moving past the eyes (e.g. overhead vents, direct air from a fan).

Therapy

Asthenopic (eye strain) symptoms in the eye are responsible for much of the severity in CVS. Proper rest to the eye and its muscles is recommended to relieve the associated eye strain. Observations from persons experiencing chronic eye strain have shown that most people who claim to be getting enough sleep are actually not. This, unaware to them, causes the eye strain to build up over a period of time, when if they had obtained seven to eight hours of uninterrupted sleep, their eye muscles would have recovered during the sleep and the strain would not have built up.[ citation needed ]

Computer workers are often advised to take breaks and look at distant objects. [4] A routinely recommended approach is to consciously blink the eyes every now and then (this helps replenish the tear film) and to look out the window to a distant object or to the sky—doing so provides rest to the ciliary muscles. [5] One of the catch phrases is the "20–20–20 rule": [6] every 20 minutes, focus the eyes on an object 20 feet (6 meters) away for 20 seconds. This basically gives a convenient distance and timeframe for a person to follow the advice from the optometrist and ophthalmologist.

A number of computer and smartphone applications adjust the computer video color temperature, reducing the amount of blue light emitted by the screen, particularly at night.

Dry eye is a symptom that is targeted in the therapy of CVS. The use of over-the-counter artificial-tear solutions can reduce the effects of dry eye in CVS. Prior to using artificial tear solutions, it is necessary to check if dry eye is the actual cause of the problem (measured by a tear meniscus test) [7] or whether there are no actual symptoms of dry eye at all. Dry eyes because of CVS can also be treated using moisture chamber glasses or humidifier machines. Office spaces with artificially dry air can worsen CVS syndromes, in which case, a desktop or a room humidifier can help the eyes keep a healthy moisture level.

At night, CVS can become worse. It is recommended to use a dark user interface while working at night on the computer. [8] Several browser and OS settings or add-ons exist to darken the user interface.

A 2017 randomized controlled trial evaluated macular carotenoid supplements (lutein, zeaxanthin, and mesozeaxanthin) in people with high screen time usage. The supplement group had statistically significant reduction in self-reported headache, eye strain, eye fatigue and sleep complaints, but no reduction in neck strain or blurry vision. [9]

A 2021 review investigated suggested therapies for CVS and found little supporting evidence for the following: switching to bi- or multi-focal glasses to reduce eye strain, or using glasses that block blue light. The same review reported "low-certainty" in omega-3 supplements as a method to combat CVS. [10]

Eyeglasses

Decreased focusing capability is mitigated by wearing a small plus-powered (+1.00 to +1.50) over-the-counter pair of eyeglasses. Wearing these eyeglasses helps such patients regain their ability to focus on near objects. People who are engaged in other occupations—such as tailors engaged in embroidery—can experience similar symptoms and can be helped by these glasses.

A Pacific University research study of 36 participants found significant differences in irritation or burning of the eyes, tearing, or watery eyes, dry eyes, and tired eyes, that were each improved by amber colored lenses versus placebo lenses, [11] but in a follow-up study in 2008, the same team was not able to reproduce the results of the first study.

A study sponsored by the lens industry has shown blue light-filtering lenses decrease specific aspects of light emissions. Theoretical reductions in phototoxicity were 10.6% to 23.6%. [12] Additionally, melatonin suppression was reduced by 5.8% to 15.0% and scotopic sensitivity by 2.4% to 9.6%. Over 70% of the participants in this testing were unable to detect these changes. The expansion of technology has led to more individuals utilizing computers and televisions which increase the overall exposure to blue light. Double-blind trials however, have shown no evidence to support the use of blue light filtering lenses for digital eye strain caused by blue light from electronic screens. [13] [14] [10]

Amber-tinted lenses have been shown to affect the circadian rhythm and treat delayed sleep phase disorder. [15] [16]

Prevalence

According to the US National Institute for Occupational Safety and Health, computer vision syndrome affects about 90% of the people who spend three hours or more a day at a computer. [17] [ unreliable medical source? ]

Another study in Malaysia was conducted on 795 university students aged between 18 and 25. The students experienced headaches along with eyestrain, with 89.9% of the students surveyed feeling any type of symptom of CVS. [18]

See also

Related Research Articles

<span class="mw-page-title-main">Glasses</span> Form of vision aid

Glasses, also known as eyeglasses and spectacles, are vision eyewear with clear or tinted lenses mounted in a frame that holds them in front of a person's eyes, typically utilizing a bridge over the nose and hinged arms, known as temples or temple pieces, that rest over the ears.

<span class="mw-page-title-main">Esotropia</span> Form of strabismus in which the eyes turn inward

Esotropia is a form of strabismus in which one or both eyes turn inward. The condition can be constantly present, or occur intermittently, and can give the affected individual a "cross-eyed" appearance. It is the opposite of exotropia and usually involves more severe axis deviation than esophoria. Esotropia is sometimes erroneously called "lazy eye", which describes the condition of amblyopia; a reduction in vision of one or both eyes that is not the result of any pathology of the eye and cannot be resolved by the use of corrective lenses. Amblyopia can, however, arise as a result of esotropia occurring in childhood: In order to relieve symptoms of diplopia or double vision, the child's brain will ignore or "suppress" the image from the esotropic eye, which when allowed to continue untreated will lead to the development of amblyopia. Treatment options for esotropia include glasses to correct refractive errors, the use of prisms, orthoptic exercises, or eye muscle surgery.

<span class="mw-page-title-main">Bates method</span> Ineffective alternative eyesight improvement therapy

The Bates method is an ineffective and potentially dangerous alternative therapy aimed at improving eyesight. Eye-care physician William Horatio Bates (1860–1931) held the erroneous belief that the extraocular muscles caused changes in focus and that "mental strain" caused abnormal action of these muscles; hence he believed that relieving such "strain" would cure defective vision. In 1952, optometry professor Elwin Marg wrote of Bates, "Most of his claims and almost all of his theories have been considered false by practically all visual scientists."

<span class="mw-page-title-main">Presbyopia</span> Medical condition associated with aging of the eye

Presbyopia is a physiological insufficiency of optical accommodation associated with the aging of the eye; it results in progressively worsening ability to focus clearly on close objects. Also known as age-related farsightedness, it affects many adults over the age of 40. A common sign of presbyopia is difficulty in reading small print, which results in having to hold reading material farther away. Other symptoms associated can be headaches and eyestrain. Different people experience different degrees of problems. Other types of refractive errors may exist at the same time as presbyopia. This condition is similar to hypermetropia or far-sightedness, which starts in childhood and exhibits similar symptoms of blur in the vision for close objects.

Photophobia is a medical symptom of abnormal intolerance to visual perception of light. As a medical symptom, photophobia is not a morbid fear or phobia, but an experience of discomfort or pain to the eyes due to light exposure or by presence of actual physical sensitivity of the eyes, though the term is sometimes additionally applied to abnormal or irrational fear of light, such as heliophobia. The term photophobia comes from Greek φῶς (phōs) 'light' and φόβος (phóbos) 'fear'.

<span class="mw-page-title-main">Strabismus</span> Eyes not aligning when looking at something

Strabismus is an eye disorder in which the eyes do not properly align with each other when looking at an object. The eye that is pointed at an object can alternate. The condition may be present occasionally or constantly. If present during a large part of childhood, it may result in amblyopia, or lazy eyes, and loss of depth perception. If onset is during adulthood, it is more likely to result in double vision.

<span class="mw-page-title-main">Intraocular lens</span> Lens implanted in the eye to treat cataracts or myopia

An intraocular lens (IOL) is a lens implanted in the eye usually as part of a treatment for cataracts or for correcting other vision problems such as short sightedness and long sightedness; a form of refractive surgery. If the natural lens is left in the eye, the IOL is known as phakic, otherwise it is a pseudophakic lens. Both kinds of IOLs are designed to provide the same light-focusing function as the natural crystalline lens. This can be an alternative to LASIK, but LASIK is not an alternative to an IOL for treatment of cataracts.

<span class="mw-page-title-main">Dry eye syndrome</span> Medical condition of dry eyes

Dry eye syndrome, also known as keratoconjunctivitis sicca, is the condition of having dry eyes. Symptoms include dryness in the eye, irritation, redness, discharge, blurred vision, and easily fatigued eyes. Symptoms range from mild and occasional to severe and continuous. Dry eye syndrome can lead to blurred vision, instability of the tear film, increased risk of damage to the ocular surface such as scarring of the cornea, and changes in the eye including the neurosensory system.

<span class="mw-page-title-main">Refractive error</span> Problem with focusing light accurately on the retina due to the shape of the eye

Refractive error is a problem with focusing light accurately on the retina due to the shape of the eye and/or cornea. The most common types of refractive error are near-sightedness, far-sightedness, astigmatism, and presbyopia. Near-sightedness results in far away objects being blurry, far-sightedness and presbyopia result in close objects being blurry, and astigmatism causes objects to appear stretched out or blurry. Other symptoms may include double vision, headaches, and eye strain.

<span class="mw-page-title-main">Diplopia</span> Double vision

Diplopia is the simultaneous perception of two images of a single object that may be displaced horizontally or vertically in relation to each other. Also called double vision, it is a loss of visual focus under regular conditions, and is often voluntary. However, when occurring involuntarily, it results from impaired function of the extraocular muscles, where both eyes are still functional, but they cannot turn to target the desired object. Problems with these muscles may be due to mechanical problems, disorders of the neuromuscular junction, disorders of the cranial nerves that innervate the muscles, and occasionally disorders involving the supranuclear oculomotor pathways or ingestion of toxins.

<span class="mw-page-title-main">Human eye</span> Sensory organ of vision

The human eye is a sensory organ in the visual system that reacts to visible light allowing eyesight. Other functions include maintaining the circadian rhythm, and keeping balance.

<span class="mw-page-title-main">Artificial tears</span> Eye drops for relieving dryness and irritation in the eye

Artificial tears are lubricating eye drops used to relieve dryness and irritation of the ocular surface. Dry eye syndrome is a common ocular surface disorder and is characterized by disruption of the tear film and increased inflammation.

Eye strain, also known as asthenopia, is a common eye condition that manifests through non-specific symptoms such as fatigue, pain in or around the eyes, blurred vision, headache, and occasional double vision. Symptoms often occur after long-term use of computers, digital devices, reading, or other activities that involve extended visual tasks which are broadly classified into external and internal symptom factors. The experience of eye strain when reading in dim light has given rise to the common misconception that such an activity causes permanent eye damage.

<span class="mw-page-title-main">Biological effects of high-energy visible light</span> Blue-light toxicity

High-energy visible light is short-wave light in the violet/blue band from 400 to 450 nm in the visible spectrum, which has a number of purported negative biological effects, namely on circadian rhythm and retinal health, which can lead to age-related macular degeneration. Increasingly, blue blocking filters are being designed into glasses to avoid blue light's purported negative effects. However, there is no good evidence that filtering blue light with spectacles has any effect on eye health, eye strain, sleep quality or vision quality.

A spasm of accommodation is a condition in which the ciliary muscle of the eye remains in a constant state of contraction. Normal accommodation allows the eye to "accommodate" for near-vision. However, in a state of perpetual contraction, the ciliary muscle cannot relax when viewing distant objects. This causes vision to blur when attempting to view objects from a distance. This may cause pseudomyopia or latent hyperopia.

<span class="mw-page-title-main">Blurred vision</span> Medical condition

Blurred vision is an ocular symptom where vision becomes less precise and there is added difficulty to resolve fine details.

<span class="mw-page-title-main">Gunnar Optiks</span> Company specializing in treated eyewear

GUNNAR Optiks is a company founded in 2007 that specializes in treated eyewear, marketed as safety glasses that protect eyes from computer vision syndrome. Gunnar eyewear has received considerable attention in technical media reviews, including PCWorld, Lifehacker, Huffington Post, and Gizmodo.

Tear break-up time (TBUT) also known as tear film break-up time (TFBUT) is the time taken for the first dry spot to appear on the cornea after a complete blink. TFBUT measurement is an easy and fast method used to assess the stability of tear film. It is a standard diagnostic procedure in the dry eye clinics. The volume of tear in the eye depends on two factors, drainage through the lacrimal passages and evaporation. Factors like decreased tear production, increased evaporation rate, tearfilm instability, tear hyperosmolarity, inflammations, ocular surface damages etc. can cause dryness to the eyes.

Exposure keratopathy is medical condition affecting the cornea of eyes. It can lead to corneal ulceration and permanent loss of vision due to corneal opacity.

The blue light spectrum, characterized by wavelengths between 400 and 500 nanometers, has a broad impact on human health, influencing numerous physiological processes in the human body. Although blue light is essential for regulating circadian rhythms, improving alertness, and supporting cognitive function, its widespread presence has raised worries about its possible effects on general well-being.

References

  1. ↑ Porcar, E.; Pons, A. M.; Lorente, A. (2016). "Visual and ocular effects from the use of flat-panel displays". International Journal of Ophthalmology. 9 (6): 881–885. doi:10.18240/ijo.2016.06.16. ISSN   2222-3959. PMC   4916147 . PMID   27366692.
  2. ↑ Izquierdo, Natalio J.; Townsend, William. "Computer Vision Syndrome". Medscape Reference: Drugs, Diseases & Procedures. WebMD LLC. Retrieved 27 February 2012.
  3. ↑ "Computer Vision Syndrome Affects Millions". 2016-05-30. Archived from the original on 2018-02-10. Retrieved 2018-04-09.
  4. ↑ Toomingas, A.; Hagberg, M.; Heiden, M.; Richter, H.; Westergren, K. E.; Tornqvist, E. Wigaeus (1 January 2014). "Risk factors, incidence and persistence of symptoms from the eyes among professional computer users". Work (Reading, Mass.). 47 (3): 291–301. doi:10.3233/WOR-131778. PMID   24284674.
  5. ↑ Randolph, SA (July 2017). "Computer Vision Syndrome". Workplace Health & Safety. 65 (7): 328. doi: 10.1177/2165079917712727 . PMID   28628753. S2CID   206831504.
  6. ↑ Brody, Jane E. (May 31, 2016). "Millions at risk of computer vision syndrome". ET Healthworld. Archived from the original on October 8, 2017. Retrieved October 7, 2017.
  7. ↑ Mainstone, J. C.; Bruce, A. S.; Golding, T. R. (June 1996). "Tear meniscus measurement in the diagnosis of dry eye". Current Eye Research. 15 (6): 653–661. doi:10.3109/02713689609008906. ISSN   0271-3683. PMID   8670769.
  8. ↑ "Dark Mode vs. Light Mode: The Great Debate". 2023-08-09. Retrieved 2024-02-14.
  9. ↑ Stringham, James; Stringham, Nicole; O’Brien, Kevin (2017). "Macular Carotenoid Supplementation Improves Visual Performance, Sleep Quality, and Adverse Physical Symptoms in Those with High Screen Time Exposure". Foods. 6 (7): 47. doi: 10.3390/foods6070047 . ISSN   2304-8158. PMC   5532554 . PMID   28661438.
  10. 1 2 Singh, Sumeer; McGuinness, Myra B.; Anderson, Andrew J.; Downie, Laura E. (October 2022). "Interventions for the Management of Computer Vision Syndrome". Ophthalmology. 129 (10): 1192–1215. doi: 10.1016/j.ophtha.2022.05.009 . PMID   35597519. S2CID   248933081.
  11. ↑ Kundart, James; John R. Hayes; Yu-Chi Tai; Jim Sheedy (2007). "Gunnar Optiks Study: Accommodation and Symptoms (2007)". Pacific University Oregon: Common Knowledge. Archived from the original on 2012-07-05. Retrieved 2012-07-28.
  12. ↑ Tsz Wing leung; Roger Wing-hong Li; Chea-su Kee (2017). "Blue-Light Filtering Spectacle Lenses: Optical and Clinical Performances". PLOS ONE . 12 (1): e0169114. Bibcode:2017PLoSO..1269114L. doi: 10.1371/journal.pone.0169114 . PMC   5207664 . PMID   28045969.
  13. ↑ M, Rosenfield; RT, Li; NT, Kirsch (2020). "A double-blind test of blue-blocking filters on symptoms of digital eye strain". Work (Reading, Mass.). 65 (2): 343–348. doi:10.3233/WOR-203086. PMID   32007978. S2CID   211012744.
  14. ↑ Singh, Sumeer; Downie, Laura; Anderson, Andrew (2021). "Do Blue-blocking Lenses Reduce Eye Strain From Extended Screen Time? A Double-Masked Randomized Controlled Trial". American Journal of Ophthalmology. 226: 243–251. doi:10.1016/j.ajo.2021.02.010. PMID   33587901. S2CID   231937552.
  15. ↑ Esaki, Yuichi; Kitajima, Tsuyoshi; Ito, Yasuhiro; Koike, Shigefumi; Nakao, Yasumi; Tsuchiya, Akiko; Hirose, Marina; Iwata, Nakao (9 April 2018). "Wearing blue light-blocking glasses in the evening advances circadian rhythms in the patients with delayed sleep phase disorder: An open-label trial". Chronobiology International. 33 (8): 1037–1044. doi:10.1080/07420528.2016.1194289. PMID   27322730. S2CID   35562927.
  16. ↑ Burkhart, Kimberly; Phelps, James R. (1 December 2009). "Amber lenses to block blue light and improve sleep: a randomized trial". Chronobiology International. 26 (8): 1602–1612. doi:10.3109/07420520903523719. PMID   20030543. S2CID   145296760.
  17. ↑ Becoming a Squinter Nation Archived 2017-04-05 at the Wayback Machine , Wall St. Journal, August 17, 2010
  18. ↑ Reddy, Chandrasekhara; Low (2013). "Computer vision syndrome: a study of knowledge and practices in university students". Neoalese Journal of Ophthalmology. 5 (2): 161–8. doi: 10.3126/nepjoph.v5i2.8707 . PMID   24172549.
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