Computer Vision Syndrome

Original Editor - Franca Ebomah

Top Contributors - Franca Ebomah, Rishika Babburu and Kim Jackson  

Introduction[edit | edit source]

Computer Vision Syndrome (CVS) has become one of the major health issues with the increased use of electronic devices with visual displays. CVS represents a group of visual and extra-ocular symptoms associated with the sustained use of visual display terminals.[1] Over 60 million people were estimated to be diagnosed with Computer Vision Syndrome.[2]It is also referred to as Visual Fatigue (VF) and Digital Eye Strain (DES)[3]

Risk Factors[edit | edit source]

  • Gender: Females are three times more predisposed to experiencing CVS than males.
  • Age: Adults 44 years and old have been found to be more at risk of developing CVS.
  • Working in a third-established university (3GU).
  • Using eye glasses
  • Workplace safety guidelines[4]
  • Longer duration of occupation and daily computer usage
  • Higher ergonomics practices knowledge: Studies reveal that individuals with higher ergonomics practices knowledge who also have longer duration of occupation and use computers daily are significantly at risk of developing CVS. This is due to failure to implement these ergonomics practices.
  • Pre-existing eye disease and use of contact lenses[2]
  • Sitting posture: Sitting in bent back position is a risk factor associated with CVS.[4]

Symptoms[edit | edit source]

The most common symptoms are[5]

These symptoms are often relieved by rest and stopping computer use [6]

The symptoms can be further divided into

  • Visual symptoms - It includes blurred vision: constant blurred vision, post work distance blur and intermittent blurred vision at near.
  • Ocular symptoms - They include eye strain, itching eyes, burning eyes, foreign body sensation, sore eyes, dysfunction of Meibomian glands[5],excessive tears and excessive blinking[8]
  • Asthenopia - Weakness of the eyes or vision
  • Light sensitivity
  • Musculoskeletal
  • General symptoms[1]

Prevalence and Burden[edit | edit source]

  • Globally, over 60 million people suffer from CVS with an incidence of 1 million people yearly.[2]
  • Symptoms of CVS affects approximately 70% of all computer customers.[4]
  • 65% of Americans suffer eye strain when using any form of digital devices. [9]
  • The burden of CVS is high in developing countries due to workload, poor knowledge of ergonomics during computer use, barrier inaccessibility and consumption of personal protective equipment. [10][11][2]
  • Asthenopia is most prevalent amongst Mexicans[12]
  • Having CVS has been found to result in 4-8% poorer-performance on work-related tasks due to visual problems[13]
  • In a study done in Spain, the overall prevalence of CVS was found to be 53% with a higher prevalence occurring among individuals wearing contact lenses.[14]

Causes[edit | edit source]

CVS results from a heightened use of electronic devices such as computers, laptops, smart phones, tablets, e-readers, and even watches for 3 hours and more daily.[4][15] The texts and images on the screens of these devices are created by combinations of tiny points of light called pixels. These pixels, which are brightest at the middle and lessen in intensity toward the edges, make it difficult for the human eye to maintain focus.[16]In addition, the following can cause symptoms of CVS:

  • Room illumination
  • Lack of screen filters
  • Screen brightness
  • Distance from the screen[17][18]
  • Poor lighting
  • Glare and reflection on the screen
  • Poor posture
  • Uncorrected vision problems
  • Or a combination of these factors[15]

It is important to note that long computer usage (more than two hours daily) by children may affect normal vision development.[9]

Assessment and Diagnosis[edit | edit source]

A comprehensive subjective and physical examination are required to assess CVS.

Subjective Assessment[edit | edit source]

  • History of CVS symptoms
  • General health problems
  • Medication use
  • Environmental factors[15]

Physical Examination[edit | edit source]

  • Visual acuity testing
  • Refraction testing
  • Eye movement, focus and synchronisation testing[15]

There are various scales available that can be used to identify CVS sufferers and grade severity of their complaints. Some of which include:

  • Visual Fatigue Scale[19]
  • The Rasch-based Computer-Vision Symptom Scale (CVSS17)[20]
  • Computer Vision Syndrome Questionnaire (CVS-Q)[14]

Management[edit | edit source]

  • Use of lubricating eye drops and blink training can be used to manage CVS symptoms such as dry eyes[3]
  • Correction of underlying eye defects such as astigmatism or presbyopia
  • Use of computer spectacles or blue-blocking lenses

Prevention and Physiotherapy Intervention[edit | edit source]

  • Education: Patients should on how to avoid eye strain. The 20-20-20 rule is an easy method to do this- take a 20-second break to view something 20 feet away every 20 minutes. Adults with children should also be educated on possible dangers of this condition.[15]Taking rest breaks also reduces eye strain.
  • Proper Ergonomics: Computer monitors 4-5 inches below eye level, measured from the center of the monitor and 20-28 inches from the eyes. Chairs should be comfortably padded and conform to the body. Chair height should be adjusted so feet rest flat on the floor. If chair has arms, they should be adjusted to provide arm support while you are typing. The wrists shouldn't rest on the keyboard when typing. Position the computer screen properly to avoid glare.[21]
  • Eye-neck exercises:

    • Sit comfortably on a chair, close both eyes and breathe deeply five times
    • Move head slowly in clockwise motion as many times as you can
    • Stand up and place both hands behind your head
    • Blink slowly ten times
    • Keep head straight. Move eyes in different directions. [21]

References[edit | edit source]

  1. 1.0 1.1 Parihar JK, Jain VK, Chaturvedi P, Kaushik J, Jain G, Parihar AK. Computer and visual display terminals (VDT) vision syndrome (CVDTS). Medical Journal Armed Forces India. 2016 Jul 1;72(3):270-6.
  2. 2.0 2.1 2.2 2.3 Ranasinghe P, Wathurapatha WS, Perera YS, Lamabadusuriya DA, Kulatunga S, Jayawardana N, Katulanda P. Computer vision syndrome among computer office workers in a developing country: an evaluation of prevalence and risk factors. BMC research notes. 2016 Dec;9(1):1-9.
  3. 3.0 3.1 Sheppard AL, Wolffsohn JS. Digital eye strain: prevalence, measurement and amelioration. BMJ open ophthalmology. 2018 Apr 1;3(1):e000146.
  4. 4.0 4.1 4.2 4.3 Zenbaba D, Sahiledengle B, Bonsa M, Tekalegn Y, Azanaw J, Kumar Chattu V. Prevalence of Computer Vision Syndrome and Associated Factors among Instructors in Ethiopian Universities: A Web-Based Cross-Sectional Study. The Scientific World Journal. 2021 Oct 5;2021.
  5. 5.0 5.1 Wu H, Wang Y, Dong N, Yang F, Lin Z, Shang X, Li C. Meibomian gland dysfunction determines the severity of the dry eye conditions in visual display terminal workers. PloS one. 2014 Aug 21;9(8):e105575.
  6. 6.0 6.1 Al Tawil L, Aldokhayel S, Zeitouni L, Qadoumi T, Hussein S, Ahamed SS. Prevalence of self-reported computer vision syndrome symptoms and its associated factors among university students. European journal of ophthalmology. 2020 Jan;30(1):189-95.
  7. Iqbal M, El-Massry A, Elagouz M, Elzembely H. Computer vision syndrome survey among the medical students in Sohag University Hospital, Egypt. Ophthalmology Research: An International Journal. 2018 Jan 5:1-8.
  8. Bogdănici CM, Săndulache DE, Nechita CA. Eyesight quality and computer vision syndrome. Romanian journal of ophthalmology. 2017 Apr;61(2):112.
  9. 9.0 9.1 Heiting G., Wan L.K. How computer glasses can ease digital strain. Available from: (Accessed on 07/01/2022)
  10. Hayes JR, Sheedy JE, Stelmack JA, Heaney CA. Computer use, symptoms, and quality of life. Optometry and vision science. 2007 Aug 1;84(8):E738-55.
  11. Shantakumari N, Eldeeb R, Sreedharan J, Gopal K. Computer use and vision. related problems among university students in Ajman, United Arab Emirate. Annals of medical and health sciences research. 2014;4(2):258-63.
  12. Sanchez-Roman FR, Perez-Lucio C, Juarez-Ruiz C, Velez-Zamora NM, Jimenez-Villarruel M. Risk factors for asthenopia among computer terminal operators. Salud pública de Mexico. 1996 May 1;38(3):189-96.
  13. Harris MG, Sheedy JE, Gan CM. Vision and task performance with monovision and diffractive bifocal contact lenses. Optometry and vision science: official publication of the American Academy of Optometry. 1992 Aug 1;69(8):609-14.
  14. 14.0 14.1 Tauste A, Ronda E, Molina MJ, Seguí M. Effect of contact lens use on computer vision syndrome. Ophthalmic and Physiological Optics. 2016 Mar;36(2):112-9.
  15. 15.0 15.1 15.2 15.3 15.4 Randolph SA. Computer vision syndrome. Workplace health & safety. 2017 Jul;65(7):328-.
  16. Heiting, G., & Wan, L. K. (2017). Computer vision syndrome and computer glasses: FAQ. All About Vision. Available from: (Accessed on 04/01/2022)
  17. Shantakumari N, Eldeeb R, Sreedharan J, Gopal K. Computer use and vision. related problems among university students in Ajman, United Arab Emirate. Annals of medical and health sciences research. 2014;4(2):258-63.
  18. Kozeis N. Impact of computer use on children's vision. Hippokratia. 2009 Oct;13(4):230.
  19. Benedetto S, Drai-Zerbib V, Pedrotti M, Tissier G, Baccino T. E-readers and visual fatigue. PloS one. 2013 Dec 27;8(12):e83676.
  20. González-Pérez M, Susi R, Antona B, Barrio A, González E. The computer-vision symptom scale (CVSS17): development and initial validation. Investigative ophthalmology & visual science. 2014 Jul 1;55(7):4504-11.
  21. 21.0 21.1 Golhar S, Bamhane S, Raka M. Effectiveness of participatory eye care programme in IT professionals with Computer Vision Syndrome. An Experimental Study. Indian Journal of Applied Research. 2021 Sept, 11(09):74-76.