Tariq AL Fayad Blog

Computer Vision Syndrome (CVS)

By Tariq Al Fayad | 4 min read

What is computer vision syndrome

Computer vision syndrome is the combination of eye and vision problems associated with the prolonged use of digital devices like computers, mobile’s, tablets. And so this computer related ocular conditions is referred as Digital Eye Strain. Nearly 60 million people in the world suffer CVS, and that a million new cases occur each year1

Symptoms2

  1. Asthenopic symptoms:  Eye stain, Tired eyes, Dry eyes.
  2. Ocular surface related: Watering eyes, Irritation, Contact lens problems.
  3. Vision problems: Blurred vision, Poor focus, Double vision, Presbyopia.
  4. Other symptoms: Neck pain, back pain, Shoulder pain because of the poor posture.

A headache & Dry eye is considered to be most common. Factors involved in drying the ocular surface are,

  • Environmental factory like dry air conditioning, dust environment etc.
  • Reduced blink rate: Normally people blink 14 – 15 times per minute. Studies have shown that blink rate decrease significantly with computer use3.
  • Increased exposure In normal reading the eyes look downwards causing the lids to cover the part of the cornea minimising the evaporation of tears. On working in computers we are viewing it in a horizontal gaze leading to increased evaporation through exposed area.
  • Age and gender. The prevalence of dry eye increases with age and is higher in women than men4.
  • Systemic diseases and medications: Moss et al.5,6 reported that the incidence of dry eye was greater in subjects with arthritis, allergy or thyroid disease not treated with hormones. Additionally, the incidence was higher in individuals taking antihistamines, anti-anxiety medications, antidepressants, oral steroids or vitamins. A lower incidence of dry eye was found with higher alcohol consumption levels.

Computer vision syndrome and children:

A computer has become a part of lifestyle at present. Children have more access to computers either at home or at schools now. Parents also encourage children at very early years to use the computers. It is believed that heavy computer use among children put them at the risk of getting early myopia. Several studies have shown it.

  • 25% - 30% of the computer using children need corrective glasses - A study at the University of California at Berkeley School of Optometry.
  • The percentage of patients who work with myopia has increased from 12.1% to 20.4% since 1995 according to a study by the department of health in Taiwan.

Prevention and treatment of CVS:

Simple setup in workplace can reduce the symptoms of CVS,

  1. Adjusting the screen brightness
  2. Refresh tears: Symptoms caused by dry eyes can be relieved by artificial refresh tears eye drops.
  3. Positioning computer screen: Computer screen should be placed 10–20° below the eye level7, away  50 to 70 cm from your face8. The improper viewing angle is identified cause Neck, back, & Shoulder pain9.
  4. Computer glasses:Those who spend 1-2 hrs per day can benefit from computer glasses. Occupational progressive lenses are designed to have a large area on top half of the lens for arms-length viewing and bottom half for near viewing (for the keyboards).

Use 20-20-20 rule: For every 20 minutes look 20 feet away object for 20 seconds. This gives your eyes rest for sometimes. Several studies reported a significant risk of getting visual symptoms when not taking frequent breaks.10,11


  1. ^

    Sen A, Richardson S. A study of computer-related upper limb discomfort and computer vision syndrome. J Hum Ergol. 2007;36(2):45–50.[PubMed]

  2. ^

    Berm M. et al An occupational study of employees with VDT associated symptoms – The importance of stress Medicine 1996; 12: 51-4.

  3. ^

    WhilePatel S, Henderson R, Bradley L et al. Effect of visual display unit use on blink rate and tear stability. Optom Vis Sci 1991; 68: 888–892.[PubMed]

  4. ^

    Salibello C & Nilsen E. Is there a typical VDT patient? A demographic analysis. J Am Optom Assoc 1995; 66: 479–483.[PubMed]

  5. ^

    Moss SE, Klein R & Klein BEK. Prevalence of and risk factors for dry eye syndrome. Arch Ophthalmol 2000; 118: 1264–1268.[PubMed]

  6. ^

    Moss SE, Klein R & Klein BEK. Long-term incidence of dry eye in an older population. Optom Vis Sci 2008; 85: 668–674.[PubMed]

  7. ^

    Anshel J. Visual ergonomics handbook. Boca Raton: CRC Press; 2005.

  8. ^

    Taptagaporn S, Sotoyama M, Saito S, Suzuki T, Saito S. Visual comfort in VDT workstation design. J Hum Ergol (Tokyo) 1995;24:84–8.[PubMed]

  9. ^

    Loh, K. Y., and S. C. Redd. "Understanding and preventing computer vision syndrome." Malaysian family physician: the official journal of the Academy of Family Physicians of Malaysia 3.3 (2008): 128.

  10. ^

    Logaraj M, Madhupriya V, Hegde S. Computer vision syndrome and associated factors among medical and engineering students in Chennai. Ann Med Health Sci Res. 2014;4(2):179–85.[PubMed Central]

  11. ^

    Rahman ZA, Sanip S. Computer user: demographic and computer-related factors that predispose user to get computer vision syndrome. Int J Bus, Humanit Technol. 2011;1(2):84–91.


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Tariq Al Fayad

Hi, I am Tariq Al Fayad, Optometrist & Private Practitioner in Tamil Nadu, India.
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