Table 9.
Univariate logistic regression analysis of factors affecting CVS occurrence (based on 5DC) (Table 1)
| Variable |
No-CVS group, n (%)
2825 (41.22) |
CVS group,
n (%) 4028 (58.78) |
OR (95% CI) | P -value |
|---|---|---|---|---|
| Sex, n (%) | ||||
| Men Women |
1417 (50.16) 1408 (49.84) |
1311 (32.55) 2717 (67.45) |
1 2.09 (1.89–2.30) |
< 0.0001 |
| Screen time, Mean ± SD | ||||
| Total daily screen hours Screen years |
6.61 ± 3.16 5.72 ± 3.42 |
7.12 ± 3.23 5.63 ± 3.16 |
1.05 (1.03–1.07) 0.99 (0.98–1.01) |
< 0.0001
0.24 |
| Screen style, n (%) | ||||
| >2 screen hours/day ≥3 screen years Night screen hours Continuous screen hours Multiple screens Small-sized screens >50% screen brightness |
2487 (88.04) 2163 (76.57) 1638 (57.98) 1205 (42.65) 1656 (58.62) 1786 (63.22) 1090 (38.58) |
3778 (93.79) 3470 (86.15) 2700 (67.03) 2177 (54.05) 2693 (66.86) 2734 (67.87) 1728 (42.90) |
2.05 (1.73–2.44) 1.90 (1.98–2.16) 1.47 (1.33–1.63) 1.58 (1.44–1.74) 1.42 (1.29–1.57) 1.23 (1.11–1.36) 1.20 (1.08–1.32) |
< 0.0001
< 0.0001 < 0.0001 < 0.0001 < 0.0001 < 0.0001 < 0.0001 |
| Screen type, n (%) | ||||
| Smartphone Laptop Pad/tablet Desktop computer |
2474 (87.58) 180 (6.37) 62 (2.19) 131 (4.64) |
3500 (86.89) 354 (8.79) 95 (2.36) 126 (3.13) |
0.94 (0.81–1.09) 1.42 (1.18–1.71) 1.08 (0.78–1.49) 0.66 (0.52–0.85) |
0.41 < 0.0001 0.66 0.001 |
| Ocular complaints, n (%) | ||||
| Blurred vision Dry eye Eye strain and fatigue Eye redness and irritation Double vision Difficulty in refocusing the eyes Near vision discomfort/difficulty Unclear objects post-screen use |
600 (21.24) 711 (25.17) 1165 (41.24) 645 (22.83) 160 (5.66) 585 (20.71) 444 (15.72) 587 (20.78) |
1911 (47.44) 2347 (58.27) 3001 (74.50) 1959 (48.63) 565 (14.03) 1765 (43.82) 1353 (33.59) 1749 (43.42) |
3.45 (3.00–3.73) 3.72 (3.35–4.12) 4.16 (3.76–4.62) 3.20 (2.87–3.56) 2.72 (2.26–3.26) 2.99 (2.67–3.33) 2.71 (2.40–3.06) 2.93 (2.62–3.27) |
< 0.0001
< 0.0001 < 0.0001 < 0.0001 < 0.0001 < 0.0001 < 0.0001 < 0.0001 |
| Extraocular complaints, n (%) | ||||
| Headache Neck/shoulder/back pain Joint pain in the fingers and wrists Inability to hold objects well Difficulty writing with a pen Sleep disturbances/ insomnia Hunger and eating late-night/midnight snacks Depression Suicidal ideation |
1313 (46.48) 1524 (53.95) 735 (26.02) 329 (11.65) 270 (9.56) 1064 (37.66) 1566 (55.43) 940 (33.27) 189 (6.69) |
3017 (74.90) 3244 (80.54) 1831 (45.46) 1095 (27.18) 915 (22.72) 2380 (59.09) 2796 (69.41) 2320 (57.60) 701 (17.40) |
3.44 (3.10–3.81) 3.53 (3.17–3.93) 2.37 (2.13–2.63) 2.83 (2.48–3.24) 2.78 (2.40–3.21) 2.39 (2.17–2.64) 1.82 (1.65–2.02) 2.72 (2.46–3.01) 2.93 (2.48–3.47) |
< 0.0001
< 0.0001 < 0.0001 < 0.0001 < 0.0001 < 0.0001 < 0.0001 < 0.0001 < 0.0001 |
| Symptoms-attacks, n (%) | ||||
| ≥2 symptoms/attacks per month over the last 12 months Symptoms/attacks occurring for at least 2 years Symptoms/attacks associated with screen use |
510 (18.05) 1027 (36.35) 1130 (40.00) |
4023 (99.88) 3176 (78.85) 4025 (99.93) |
3652 (1511–8825) 6.24 (5.61–6.95) 2012 (647.18–6257) |
< 0.0001
< 0.0001 < 0.0001 |
| Medical studies, n (%) | ||||
| Mandated Computer System Use Program Screens as a main study source Medicine/science consuming most of screen time |
1750 (61.95) 1873 (66.30) 1719 (60.85) |
3058 (75.92) 3000 (74.48) 2710 (67.28) |
1.94 (1.74–2.15) 1.48 (1.33–1.65) 1.32 (1.20–1.46) |
< 0.0001
< 0.0001 < 0.0001 |
| Previous dry eye disease, n (%) | 661 (23.40) | 1759 (43.67) | 2.53 (2.28–2.82) | < 0.0001 |
| Refractive error, n (%) | 1208 (42.76) | 2365 (58.71) | 1.90 (1.72–2.10) | < 0.0001 |
| Contact lens wearing, n (%) | 223 (7.89) | 523 (12.98) | 1.74 (1.48–2.05) | < 0.0001 |
| Poor screen resolution or design, n (%) | 462 (16.35) | 1050 (26.07) | 1.80 (1.60–2.04) | < 0.0001 |
| Screen glare, n (%) | 385 (13.63) | 973 (24.16) | 2.02 (1.77–2.30) | < 0.0001 |
| Screen edge at/above horizontal eye level, n (%) | 603 (21.35) | 1462 (36.30) | 2.10 (1.88–2.34) | < 0.0001 |
| Close eye-to-screen distance, n (%) | 882 (31.22) | 2253 (55.93) | 2.80 (2.53–3.09) | < 0.0001 |
| Poor lighting conditions, n (%) | 909 (32.18) | 1981 (49.18) | 2.04 (1.85–2.25) | < 0.0001 |
| Watching screen in the dark, n (%) | 1579 (55.89) | 2696 (66.93) | 1.60 (1.45–1.76) | < 0.0001 |
| Uncomfortable sitting postures, n (%) | 1305 (46.19) | 2712 (67.33) | 2.40 (2.17–2.65) | < 0.0001 |
| Small font size, n (%) | 821 (29.06) | 1739 (43.17) | 1.85 (1.67–2.05) | < 0.0001 |
| Texting with both thumbs, n (%) | 1249 (44.21) | 2262 (56.16) | 1.62 (1.46–1.78) | < 0.0001 |
Abbreviations: OR, odds ratio; CI, confidence interval; CVS, computer vision syndrome; 5DC (Table 1), five subjective diagnostic criteria for accurate computer vision syndrome diagnosis. Note: P-values < 0.05 are shown in bold.