Computer vision syndrome (CVS) is a condition resulting from focusing the

eyes Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and conve ...

on a

computer A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as C ...

or other

display device A display device is an output device for presentation of information in visual or tactile form (the latter used for example in tactile electronic displays for blind people). When the input information that is supplied has an electrical signal the ...

for protracted, uninterrupted periods of

time Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, into the future. It is a component quantity of various measurements used to sequence events, to ...

and the eye's muscles being unable to recover from the constant tension required to maintain focus on a close object. Some

symptom Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showin ...

s of CVS include

headache Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches. Headaches can occur as a result ...

s, blurred vision, neck pain,

fatigue Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...

eye strain Eye strain, also known as asthenopia (from Greek ''a-sthen-opia'', grc, ἀσθενωπία, ), is a common eye condition that manifests through non-specific symptoms such as fatigue, pain in or around the eyes, blurred vision, headache, and ...

dry eyes Dry eye syndrome (DES), also known as keratoconjunctivitis sicca (KCS), is the condition of having dry eyes. Other associated symptoms include irritation, redness, discharge, and easily fatigued eyes. Blurred vision may also occur. Symptoms rang ...

, irritated eyes, double vision,

vertigo Vertigo is a condition where a person has the sensation of movement or of surrounding objects moving when they are not. Often it feels like a spinning or swaying movement. This may be associated with nausea, vomiting, sweating, or difficulties w ...

dizziness Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to disequilibrium or a non-specific feeling, such as giddiness or foolishness. Dizziness is a common medical c ...

, polyopia, and difficulty refocusing the eyes. These symptoms can be further aggravated by improper lighting conditions (i.e. glare, strong blue-spectrum

backlight A backlight is a form of illumination used in liquid crystal displays (LCDs). As LCDs do not produce light by themselves—unlike, for example, cathode ray tube (CRT), plasma (PDP) or OLED displays—they need illumination ( ambient light or a ...

s, 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

. 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 . Computer workers are often advised to take breaks and look at distant objects. 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 The ciliary muscle is an intrinsic muscle of the eye formed as a ring of smooth muscleSchachar, Ronald A. (2012). "Anatomy and Physiology." (Chapter 4) . in the eye's middle layer, uvea (vascular layer). It controls accommodation for viewing o ...

. One of the catch phrases is the "20–20–20 rule": every 20

minute The minute is a unit of time usually equal to (the first sexagesimal fraction) of an hour, or 60 seconds. In the UTC time standard, a minute on rare occasions has 61 seconds, a consequence of leap seconds (there is a provision to insert a nega ...

s, focus the eyes on an object 20 feet (6 meters) away for 20

second The second (symbol: s) is the unit of time in the International System of Units (SI), historically defined as of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds ...

s. This basically gives a convenient distance and timeframe for a person to follow the advice from the

optometrist Optometry is a specialized health care profession that involves examining the eyes and related structures for defects or abnormalities. Optometrists are health care professionals who typically provide comprehensive primary eye care. In the Uni ...

and

ophthalmologist Ophthalmology ( ) is a surgery, surgical subspecialty within medicine that deals with the diagnosis and treatment of eye disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Followin ...

. A number of computer and smartphone applications, such as f.lux,

redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in f ...

and Night Shift adjust the computer video color temperature, reducing the amount of

blue light Blue Light or Blue light may refer to: Science and technology * Portion of the visible spectrum related to the blue color ** Blue laser ** Blue LED * Cherenkov radiation, the physical phenomenon responsible for the characteristic blue glow in nucl ...

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) 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. Several browser and OS add-ons exist to darken the user interface. A 2017 randomized controlled trial evaluated macular

carotenoid Carotenoids (), also called tetraterpenoids, are yellow, orange, and red organic compound, organic pigments that are produced by plants and algae, as well as several bacteria, and Fungus, fungi. Carotenoids give the characteristic color to pumpki ...

supplements (

lutein Lutein (;"Lutein"

zeaxanthin Zeaxanthin is one of the most common carotenoids in nature, and is used in the xanthophyll cycle. Synthesized in plants and some micro-organisms, it is the pigment that gives paprika (made from bell peppers), corn, saffron, goji ( wolfberries), ...

, 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. 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

. The same review reported "low-certainty" in omega-3 supplements as a method to combat CVS.

Eyeglasses

Decreased focusing capability is mitigated by wearing a small plus-powered (+1.00 to +1.50) over-the-counter pair of

eyeglasses Glasses, also known as eyeglasses or spectacles, are vision eyewear, with lenses (clear or tinted) 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 ...

. 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 Embroidery is the craft of decorating fabric or other materials using a needle to apply thread or yarn. Embroidery may also incorporate other materials such as pearls, beads, quills, and sequins. In modern days, embroidery is usually seen on c ...

—can experience similar symptoms and can be helped by these glasses. A

Pacific University Pacific University is a private university in Forest Grove, Oregon. Founded in 1849 as the Tualatin Academy, the original Forest Grove campus is west of Portland. The university maintains three other campuses in Eugene, Hillsboro, and Wood ...

research study of 36 participants found significant differences in irritation or burning of the eyes, tearing, or watery eyes,

, and tired eyes, that were each improved by amber colored lenses versus

placebo A placebo ( ) is a substance or treatment which is designed to have no therapeutic value. Common placebos include inert tablets (like sugar pills), inert injections (like Saline (medicine), saline), sham surgery, and other procedures. In general ...

lenses, but in a follow-up study in 2008, the same team was not able to reproduce the results of the first study. Competing research has shown blue light-filtering lenses decrease specific aspects of light emissions. Theoretical reductions in

phototoxicity Phototoxicity, also called photoirritation, is a chemically induced skin irritation, requiring light, that does not involve the immune system. It is a type of photosensitivity. The skin response resembles an exaggerated sunburn. The involved chemi ...

were 10.6% to 23.6%. Additionally,

melatonin Melatonin is a natural product found in plants and animals. It is primarily known in animals as a hormone released by the pineal gland in the brain at night, and has long been associated with control of the sleep–wake cycle. In vertebrates ...

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. This has opened up opportunities for companies such as

Gunnar Optiks 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 P ...

and

Razer Inc. Razer Inc. is an American-Singaporean multinational technology company that designs, develops, and sells consumer electronics, financial services, and gaming hardware. Founded by Min-Liang Tan and Robert "RazerGuy" Krakoff, it is dual headqu ...

to create glasses focused on reducing the 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. Amber-tinted lenses have been shown to affect the

circadian rhythm A circadian rhythm (), or circadian cycle, is a natural, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours. It can refer to any process that originates within an organism (i.e., Endogeny (biology), endogeno ...

and treat

delayed sleep phase disorder Delayed sleep phase disorder (DSPD), more often known as delayed sleep phase syndrome and also as delayed sleep–wake phase disorder, is a delaying of a person's circadian rhythm (biological clock) compared to those of societal norms. The diso ...

Prevalence

According to the US

National Institute for Occupational Safety and Health The National Institute for Occupational Safety and Health (NIOSH, ) is the United States federal agency responsible for conducting research and making recommendations for the prevention of work-related injury and illness. NIOSH is part of the C ...

, computer vision syndrome affects about 90% of the people who spend three hours or more a day at a computer. 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.

References

External links

* * {{cite journal, author=Yan, first=Zheng, last2=Hu, first2=Liang, last3=Chen, first3=Hao, last4=Lu, first4=Han, title=Computer Vision Syndrome: A widely spreading but largely unknown epidemic among users, url=https://www.sciencedirect.com/science/article/pii/S0747563207001501, journal=Computers in Human Behavior, volume=24, issue=5, date=September 2008, pages=2026–2042, doi=10.1016/j.chb.2007.09.004 Eye diseases Overuse injuries Syndromes Occupational diseases

Therapy

Eyeglasses

Prevalence

See also

References

External links