Table 1.
Studies with symptom scores only.
| Study (location) | Sample | Design | Preventive measure/protective effect | Follow‐Up | Outcome |
|---|---|---|---|---|---|
| Telles et al. 2006 (IN) | 281 computer workers | Single‐blinded RCT | 1 hr/day of yoga, 5 day/week | 60 days | Yoga increased visual comfort, whilst the control group decreased in visual comfort at the same time |
| Amick et al. 2011 (US) | 184 office workers | Prospective, controlled | Ergonomic chair + ergonomic training | 12 months | Those receiving both ergonomic chairs and training saw a greater improvement in their ocular symptoms than controls, and the group receiving ergonomic training only. Ergonomic training alone did not perform better than the control group |
| Menéndez et al. 2011 (US) | 154 office workers | Prospective, controlled | Ergonomic chair + ergonomic training | 12 months | The group receiving training only and the group receiving chair + ergonomic training had improved ocular symptoms after the intervention, compared to the control group |
| Sitaula et al. 2018 (NP) | 236 students (29% DED symptoms) | Cross‐sectional | <2 hr/day computer use and VDT below eye level | NA | VDT <2 hr/day was associated with substantially fewer CVS symptoms than >2 hr/day (31% versus 95%). Screen height below eye level was not found protective for CVS symptoms |
| Ranasinghe et al. 2016 (LK) | 2210 office workers (31% DED symptoms) | Cross‐sectional | VDT filter, distance to screen, ergonomics knowledge, breaks, background lighting, type of monitor | NA | Short occupational history and low daily VDT time, using a VDT filter and adjusting screen brightness to ambient light were associated with a lower prevalence of CVS. Type of VDT monitor, distance to screen, background lighting, and the number of breaks were not associated with CVS prevalence or severity |
| Altalhi et al. 2020 (SA) | 334 students (48% DED symptoms) | Cross‐sectional | Reduced glare on screen, frequent breaks, low angle of gaze | NA | Students with less screen glare on VDT were less likely to have CVS symptoms. Automatic screen brightness, taking breaks, angle of gaze, and < 6 hr/day of VDT time were not associated with fewer CVS symptoms |
| Logaraj, et al. 2014 (IN) | 416 students | Cross‐sectional | Breaks every hr | NA | Students taking breaks after 1 hr of computer had less dry eye symptoms than those breaking after 2 hr of continuous use |
| Mowatt et al. 2018 (JM) | 409 students (29% DED diagnosis) | Cross‐sectional | Angle of gaze, adjustable chair and frequency of brakes | NA | Ergonomic practices such as an adjustable chair and taking breaks at least every 3 hr were associated with reduced severity of dry eye symptoms. 43% of users holding their device in their hands had moderate dry eye symptoms, compared to only 22% using the device on a desk |
| Zayed et al. 2021 (EG) | 126 students | Cross‐sectional | Anti‐glare screen, AC, high relative humidity, adjusting screen brightness and distance to screen | NA | CVS users maintaining <51 cm to screen had less CVS symptoms. Use of AC, exposure to a windy environment and a low relative humidity was associated with ocular complaints. Using anti‐glare screens and adjusting screen brightness was associated with low CVS prevalence |
Dashed line: line splits prospective, interventional and cross‐sectional, observational studies.
AC = air‐condition, CVS = computer vision syndrome, DED = dry eye disease, DED = dry eye disease, NA = not applicable, RCT = randomized controlled trial, VDT = video display terminal.