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

eyes An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

on a

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

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 signa ...

for protracted, uninterrupted periods of

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

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

Symptoms

Some

symptom Signs and symptoms are diagnostic indications of an illness, injury, or condition. Signs are objective and externally observable; symptoms are a person's reported subjective experiences. A sign for example may be a higher or lower temperature ...

s of CVS include

headache A headache, also known as cephalalgia, 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 (mood), depression in those with severe ...

blurred vision Blurred vision is an ocular symptom where vision becomes less precise and there is added difficulty to resolve fine details. Temporary blurred vision may involve dry eyes, eye infections, alcohol poisoning, hypoglycemia, or low blood pressur ...

, neck pain,

fatigue Fatigue is a state of tiredness (which is not sleepiness), exhaustion or loss of energy. It is a signs and symptoms, symptom of any of various diseases; it is not a disease in itself. Fatigue (in the medical sense) is sometimes associated wit ...

eye strain Eye strain, also medically termed as asthenopia (), is a common eye condition characterized by nonspecific symptom, non-specific symptoms such as fatigue, pain in or around the eyes, blurred vision, headache, and occasional diplopia, double vis ...

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 occa ...

, irritated eyes, double vision,

vertigo Vertigo is a condition in which a person has the sensation that they are moving, or that objects around them are moving, when they are not. Often it feels like a spinning or swaying movement. It may be associated with nausea, vomiting, perspira ...

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

, 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) that provides light from the back or side of a display panel. LCDs do not produce light on their own, so they require illumination—either from available light, ambie ...

s, or bright overhead lighting) or air moving past the eyes (e.g. overhead vents, or 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. One of the catch phrases is the "20–20–20 rule": every 20

minute A minute is a unit of time defined as equal to 60 seconds. It is not a unit in the International System of Units (SI), but is accepted for use with SI. The SI symbol for minutes is min (without a dot). The prime symbol is also sometimes used i ...

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

second The second (symbol: s) is a unit of time derived from the division of the day first into 24 hours, then to 60 minutes, and finally to 60 seconds each (24 × 60 × 60 = 86400). The current and formal definition in the International System of U ...

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

optometrist Optometry is the healthcare practice concerned with examining the eyes for visual defects, prescribing corrective lenses, and detecting eye abnormalities. In the United States and Canada, optometrists are those that hold a post-baccalaureate f ...

and

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

. 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) 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 settings or add-ons exist to darken the user interface. A 2017 randomized controlled trial evaluated macular

carotenoid Carotenoids () are yellow, orange, and red organic pigments that are produced by plants and algae, as well as several bacteria, archaea, and fungi. Carotenoids give the characteristic color to pumpkins, carrots, parsnips, corn, tomatoes, cana ...

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 blue light. 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 (American English), spectacles (Commonwealth English), or colloquially as specs, are Visual perception, vision eyewear with clear or tinted lens (optics), lenses mounted in a frame that holds them in front ...

. 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 art of decorating Textile, fabric or other materials using a Sewing needle, needle to stitch Yarn, thread or yarn. It is one of the oldest forms of Textile arts, textile art, with origins dating back thousands of years across ...

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

Pacific University Pacific University is a private university in Forest Grove, Oregon, United States. Founded in 1849 as the Tualatin Academy, the original Forest Grove campus is west of Portland. Affiliated with the United Church of Christ, the school mainta ...

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 ( ) can be roughly defined as a sham medical treatment. Common placebos include inert tablets (like sugar pills), inert injections (like saline), sham surgery, and other procedures. Placebos are used in randomized clinical trials ...

lenses, 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 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 chem ...

were 10.6% to 23.6%. Additionally,

melatonin Melatonin, an indoleamine, is a natural compound produced by various organisms, including bacteria and eukaryotes. Its discovery in 1958 by Aaron B. Lerner and colleagues stemmed from the isolation of a substance from the pineal gland of cow ...

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. Amber-tinted lenses have been shown to affect the

circadian rhythm A circadian rhythm (), or circadian cycle, is a natural oscillation that repeats roughly every 24 hours. Circadian rhythms can refer to any process that originates within an organism (i.e., Endogeny (biology), endogenous) and responds to the env ...

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 the delaying of a person's circadian rhythm (biological clock) compared to those of societal norms. The dis ...

Prevalence

According to the US

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

, 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, url-access=subscription Eye diseases Overuse injuries Syndromes affecting the eye Occupational diseases Syndromes affecting muscles

Symptoms

Therapy

Eyeglasses

Prevalence

See also

References

External links