Table of Contents

2019 Month : November Volume : 6 Issue : 46 Page : 2935-2939

The Impact of Video Display Terminals on Ocular and Non-Ocular Health Among Students: A Cross-Sectional Study

Jasmita Satapathy1, Adyasha Dash2

1. Associate Professor, Department of Ophthalmology, Institute of Medical Sciences and SUM Hospital, Bhubaneswar, Odisha.
2. Senior Resident, Department of Ophthalmology, Institute of Medical Sciences and SUM Hospital, Bhubaneswar, Odisha.

Corresponding Author:
Dr. Adyasha Dash,
Department of Ophthalmology,
Institute of Medical Sciences and SUM Hospital, Bhubaneswar, Odisha.
DOI: 10.18410/jebmh/2019/612

Extensive use of various video display terminals (VDT) including smart phones for learning as well as for other fun activities by the students has generated concerns related to potential health hazards associated with their use. The aim of this study was to assess the prevalence of computer vision syndrome (CVS) & associated non-ocular problems, and to spread awareness about the deleterious effects of various VDTs among the students of SOA Deemed to be University, Odisha, India.

A questionnaire-based survey was done among the students of SOA Deemed to be University from September 2018 to March 2019. A total 1141 students participated in the survey. Details on awareness about Computer Vision Syndrome, extent of the VDT use, ocular symptoms and non-ocular health issues related to CVS were recorded. Also, the students were given a brief idea about the adverse effects of prolonged use of such gadgets and the protective measures to be taken to avoid the problems.

A total of 1141 students, aged between 17 and 25 years, from different educational backgrounds of a university in eastern India were surveyed. The prevalence of symptoms of CVS (one or more) was found to be 87.82%. The most frequently reported symptom was headache (56.79%) followed by watering (43.12%) and eye strain (42.59%). Students who used the video display terminals for more than 2 hours per day experienced CVS more than those who use for less than 2 hours. Along with ocular symptoms various non ocular health problems were also reported. Among them neck pain and drowsiness were frequently reported symptoms. Taking frequent breaks in between was associated with less symptoms of CVS.

Awareness of CVS among the students is very less. As far as possible, use of video display terminals including the smart phones has to be minimised. Mass awareness should be created especially among the younger population through various means of communication to reduce the risk of such health issues related to these gadgets.

Computer Vision Syndrome, Video Display Terminals, Students, Non-Ocular Health Issues

How to cite this article

Satapathy J, Dash A. The impact of video display terminals on ocular and non-ocular health among students: a cross-sectional study. J. Evid. Based Med. Healthc. 2019; 6(46), 2935-2939. DOI: 10.18410/jebmh/2019/612


Computers and mobile phones have become a basic necessity of life now-a-days. Most of the workplaces, schools, colleges and even at homes varieties of digital gadgets are used regularly. Affordable price of such devices, the technological advance, the demand of the society and easy availability of internet connection have created a conducive environment for a large proportion of population to use them. Studies have shown that these gadgets have a great impact on ocular and non- ocular health.1,2,3,4 Their extensive use can lead to computer vision syndrome.5 Along with that various musculoskeletal6,7,8 and psychological problems can also arise when they are used improperly. The Occupational safety and health administration (OSHA) department of the US Government has defined CVS as a complex of eye and vision problems that are experienced during and related to computer use. CVS includes the asthenopic symptoms of burning, itching, foreign body sensation, watery eye, excessive blinking, eye redness, eye strain, eye fatigue, blurred vision, dry eye, double vision, difficulty in focusing for near objects, increase sensitivity to light, coloured halos around objects and headache that occur as a result of computer use.


The study locations were all the educational institutes under SOA Deemed to be University. It included students of IMS (Institute of Medical Science), IDS (Institute of Dental Science), ITER (Institute of Technical Education and Research), SNC (SUM Nursing College), SPS (School of Pharmaceutical Sciences), SNIL(SOA National Institute of Law), SHM (School of Hotel Management), IBCS(Institute of Business and Computer Studies), IAS (Institute of Agricultural Sciences) and CBT (Centre for Biotechnology). The number of participants to be included from each institute was determined by the probability proportionate to sample size (PPS) method depending on population data for each institute. Inclusion criteria was students who use VDTs for at least 1 hour per day and had used for at least 1 year. Simple random sampling was done to select the participants. After taking due permission from the respective authorities in the above-mentioned institutes, an interactive session was arranged, and all the students were invited to attend the session. Attendance was taken and every alternate present student was selected as a participant. Informed written consent was obtained from each participant. Ethical approval for the study was obtained from the Ethics review committee of SOA Deemed to be University, Bhubaneswar, Odisha. The survey was conducted between September 2018 to March 2019.

A structured questionnaire was framed and used to collect socio-demographic data, details of VDT usage, ocular and non-ocular symptoms of CVS, potential risk factors, the preventive measures and the awareness about CVS. To establish the validity of the questionnaire a sub-group of 50 students were evaluated for dry eye by doing Schirmer test. The test was done by an Ophthalmic assistant to avoid bias and the result was written at the back of the respective filled questionnaire. Total 1141 students were participated in the survey by answering the questionnaire. The data thus collected was entered in an Excel sheet for further statistical analysis. Data was analysed using Microsoft Excel file. The descriptive data were presented as percentages or as mean ± standard deviations. Z proportion test was used to calculate p value. P< 0.05 was taken as significant.



Age in Years












Table 1. Age Distribution of Students


A total 1141 students participated in the survey. The mean age of the study population was 20.53 years ± 1.47 years. Table 1 shows the age distribution of the study population in years. Majority of participants were females 54.25% (n=619) and males accounted for 45.75% (n=522). About 38.38% (438/1141) were medical students, 31.90% (364/1141) were engineering students and rest 29.72% (339/1141) were students of other (dental, nursing, biotechnology etc) educational background. Around 31.63% (361) students were using more than one gadget. Almost all were using smartphones frequently. Very few were using desktop and laptop. Table 2 shows ocular symptoms seen among the participants. Presence of one or more symptom was considered as computer vision syndrome. The prevalence of CVS was found to be 87.82% (n=1002). Headache was the most commonly reported symptom. About 88.95% (1015) students reported musculoskeletal symptoms like neck pain, back pain, shoulder pain and pain in arm. Out of them 42% had more than one symptom (Table 3).








Eye strain






Eye fatigue



Blurring vision






Burning sensation



Dry eye






FB sensation






Table 2. Symptoms of CVS Seen Among the Students





Neck pain



Back pain



Shoulder pain



Pain in arm



Table 3. Musculoskeletal Symptoms Seen Among the Students


General symptoms like irritability, nervousness, drowsiness and fatigue were found in 45% students. Among these symptoms, most frequently reported symptom was drowsiness. Appropriate posture was maintained in only 22.96% (262/1141) cases. Rest of the students adopt inappropriate sitting and/or lying posture. Around 602(52.76%) students use the gadget mostly in lying down posture. Musculoskeletal symptoms were found to be more associated with inappropriate posture (89.64%). Only 153 students keep the gadget at more than 50 cm distance while use. Rest of the students (n=988, 86.59%) use the gadget at less than 50 cm distance. Table 4 shows distribution of study population according to the duration of use of gadgets. As CVS is a transient problem, duration was not found to have significance.


Duration in Years



Less than 5 years









Table 4. Distribution of Students According to the Duration of Use of Gadgets




Percentage of CVS
















< 5 years

5-10 years

>10 years
















Time Spent Daily

Less than equal to 2 hrs

More than 2 hrs









91.40 P=0.023


>20 min or no break









90.00 P= 0.047

Table 5. Comparison of Variables Among CVS and

Non-CVS Group


About 37.77% (431) used the gadget for less than 2 hours per day, 46.36% (529) use for 2-4 hours per day and 15.87% (181) use for more than 4 hours per day. Students who use the gadgets for more than 2 hours were found to have the symptoms of CVS more. 958 (83.96%) students take break while using the gadget. Out of them only 418 (43.63%) students take break in every 20 minutes or less. Students who take break less frequently were found to develop the symptoms of CVS more. Among the total study population, 660 (57.84%) students use glasses. Out of them 619 students use glasses for refractive error and only 41 students use glasses as protective measure while using computer and related gadgets. Around 226 (19.81%) students follow the rule of voluntary blinking while using the video display terminals. Only 301(26.38%) students were aware of computer vision syndrome. These 26% students were using one or more protective measures like cold compress, ARC glasses, lubricating eye drops etc., while using video display terminals. Table 5 shows the comparison of variables like posture, duration of use, time spent daily, and break taken among CVS and non-CVS group. Amount of time spent daily, and frequency of breaks taken were found to be significantly associated with CVS.


This study was conducted among 1141 university students. The self-reported prevalence of CVS was found to be 87.82%. This is in line with the results reported in Malaysia among university students, which was 89.9%,9 and in Chennai among medical and engineering students, which was 80.3%.5 However the result was more than the findings of other studies: 69.5% in Debre Tabor Town, Northwest Ethiopia, among government office workers;10 73.9% in University of Gondar, Ethiopia, among secretaries and data processors;11 73% in Gondar, Ethiopia, among bank workers;12 74% in Abuja, Nigeria;13 67.4% in Sri Lanka among office workers;14 72% in Ajman, United Arab Emirates;15 and 63% in Public University of Putra, Malaysia, among administrative staffs.16 This could be due to the participants in our study being the university students who use smart phones and similar gadgets for longer time without taking frequent breaks both for study purpose and for entertainment.

This study found headache as the most common symptom of CVS (56.79%). Similar result (61%) was reported by Sen and Richardson.17 About 43.3% medical and 45% of engineering students complained headache in the study by Logaraj et al.5 Whereas a lower prevalence was found by Talwar et al.4 Amount of time spent daily in-front of VDT was an important factor that was found to be statistically significant in the present study. Students who spent more than two hours daily were more likely to develop CVS as compared to those who spent less than two hours (p=0.023). Kharel et al18 found that students spending more than 2-3 hours on computer daily have a higher risk of developing CVS. Awrajaw Dessie et al10 reported that respondents who used computer for more than 4.6 hours daily were at higher risk of developing CVS. Many other studies have found that visual symptoms increased significantly with the increase in working hours on the computer.1,3,5,14,19,20 Therefore CVS may be prevented by reducing daily exposure. However, duration of VDT use was not found to be statistically significant in this study.

Those working for more than 20 minutes without break were more likely to suffer from CVS as compared to those taking break within 20 minutes (p=0.047). This could be because the eyes normally cannot remain focused on the pixel-generated images on a computer screen for a long time, and as such, the eyes must focus and refocus thousands of times by taking frequent breaks for adequate time while viewing the screen, and if the refresh rate is too slow, it causes a high flickering screen, which leads to suffer from symptoms of CVS.12 The result was in line with previous studies who reported that taking break is a protective factor for CVS.5,12,15 Taking short breaks of 5 minutes after working for one hour has been shown to decrease eye and musculoskeletal problem without undue influence of work productivity.21 It has been recommended that the user should look at a distant object away from the screen at least once in every 30 minutes to one hour.22 This provides relief from accommodative spasm and glare from the screen.23

In this study about 89% respondents reported various musculoskeletal symptoms like neck pain, shoulder pain, back pain and pain in arm. Among these symptoms neck pain was found to be most common (57%). This result was in line with the study by Tawil et al24 82.2%. In the study by Logaraj et al5 61% students reported neck and shoulder pain. Similar findings were reported by various other studies.6,7,25 In contrast, Diepenmaat et al8 have reported a low prevalence (11.5%) of neck and shoulder pain among adolescents. Studies have shown that use of protective measures including ARC glasses and frequent blinking were less associated with asthenopic symptoms like dry eye and headache.26,27 However in our study very few students (<20%) were using these protective measures. Hence their association could not be analysed. Moreover only 301(26.38%) students out of 1141 students were aware about CVS. The awareness among the students was found to be very low which might be the reason of high prevalence of CVS in our study. Similar finding was seen in the study by Kharel et al18 who reported only 22.9% had pre-existing knowledge of CVS.


Students are exposed to different gadgets in the form of desktop, laptop, tablet and smart phones. Such exposure may or may not be a part of their course curriculum. Many of them are using the VDTs for a prolonged period of time as a device for fun and entertainment, which has many adverse effects. This study will make people aware of such avoidable problems.




  1. Rajeev A, Gupta A, Sharma M. Visual fatigue and computer use among college students. Indian J Community Med 2006;31(3):192-193.
  2. Sharma AK, Khera S, Khandekar J. Computer related health problems among information technology professionals in Delhi. Indian J Community Med 2006;31(1):36-38.
  3. Shrivastava SR, Bobhate PS. Computer related health problems among software professionals in Mumbai: a cross-sectional study. Int J Health Sci 2012;1(2):74-78.
  4. Talwar R, Kapoor R, Puri K, et al. A study of visual and musculoskeletal health disorders among computer professionals in NCR Delhi. Indian J Community Med 2009;34(4):326-328.
  5. Logaraj M, Madhupriya V, Hegde SK. Computer vision syndrome and associated factors among medical and engineering students in Chennai. Ann Med Health Sci Res 2014;4(2):179-185.
  6. Wahlstrom J. Ergonomics, musculoskeletal disorders and computer work. Occup Med (Lond) 2005;55(3):168-176.
  7. Jacobs K, Baker NA. The association between children's computer use and musculoskeletal discomfort. J Prev Assess Rehabil 2002;18:221-226.
  8. Diepenmaat AC, van der Wal MF, de Vet HC, et al. Neck/shoulder, low back, and arm pain in relation to computer use, physical activity, stress, and depression among Dutch adolescents. Pediatrics 2006;117(2):412-416.
  9. Reddy SC, Low CK, Lim YP, et al. Computer vision syndrome: a study of knowledge and practices in university students. Nepal J Ophthalmol 2013;5(2):161-168.
  10. Dessie A, Adane F, Nega A, et al. Computer vision syndrome and associated factors among computer users in Debre tabor town, Northwest Ethiopia. Journal of Environmental and Public Health 2018;2018:1-8.
  11. Alemayehu M, Nega A, Tegegne E, et al. Prevalence of self-reported computer vision syndrome and associated factors among secretaries and data processors who are working in University of Gondar, Ethiopia. Journal of Biology, Agriculture and Healthcare 2014;4(15):33-37.
  12. Assefa NL, Weldemichael DZ, Alemu HW, et al. Prevalence and associated factors of computer vision syndrome among bank workers in Gondar City, northwest Ethiopia. Clinical Optometry 2017;9:67-76.
  13. Akinbinu TR, Mashalla Y. Knowledge of computer vision syndrome among computer users in the workplace in Abuja, Nigeria. Journal of Physiology and Pathophysiology 2013;4(4):58-63.
  14. Ranasinghe P, Wathurapatha WS, Perera YS, et al. Computer vision syndrome among computer office workers in a developing country: an evaluation of prevalence and risk factors. BMC Res Notes 2016;9:150.
  15. Shantakumari N, Eldeeb R, Sreedharan J, et al. Computer use and vision related problems among university students in Ajman, United Arab emirate. Ann Med Health Sci Res 2014;4(2):258-263.
  16. Zainuddin H, Isa MM. Effect of human and technology interaction: computer vision syndrome among administrative staff in a public university. Int J of Business, Humanities and Technology 2014;4(3):39-43.
  17. Sen A, Richardson S. A study of computer-related upper limb discomfort and computer vision syndrome. J Hum Ergol (Tokyo) 2007;36(2):45-50.
  18. Kharel SR, Khatri A. Knowledge, Attitude and practice of Computer Vision Syndrome among medical students and its impact on ocular morbidity. J Nepal Health Res Counc 2018;16(3):291-296.
  19. Sharma AK, Khera S, Khandekar J. Computer related health problems among information technology professionals in Delhi. Indian J Community Med 2006;31(1):36-38.
  20. Rahman ZA, Sanip S. Computer user: demographic and computer related factors that predispose user to get computer vision syndrome. Int J Business, Humanities and Technology 2011;1(2):84-91.
  21. Levy BS. Preventing Occupational Disease and Injury. American Public Health Association, Washington, DC, USA, 2005.
  22. Cheu RA. Good vision at work. Occup Health Saf 1998;67:20-24.
  23. Ganong WF. Review of medical physiology. 22nd New York; Lange Publication 2005.
  24. Tawil LA, Aldokhayel S, Zeitouni L, et al. Prevalence of self-reported computer vision syndrome symptoms and its associated factors among university students. Eur J Ophthalmol 2018. DOI: 10.1177/1120672118815110.
  25. Lorusso A, Bruno S, L'Abbate N. Musculoskeletal disorders among university student computer users. Med Lav 2009;100(1):29-34.
  26. Abdelaziz M, Fahim SA, Mousa DB, et al. Effects of computer use on visual acuity and colour vision. Eur J Sci Res 2009;35:99-105.
  27. Miyake-Kashima M, Dogru M, Nojima T, et al. The effect of antireflection film use on blink rate and asthenopic symptoms during visual display terminal work. Cornea 2005;24(5):567-570.