Table 2.
Demographical data and digital device usage characteristics
| Demography | Number (%) |
|---|---|
| Mean age (years) ± SD | 9.72±3.02 (range: 7-18) |
| Male: Female | 332:360 |
| Class | |
| Primary school | 433 (62.5%) |
| Elementary school | 180 (26.0%) |
| High school | 79 (11.4%) |
| Devices for online class | |
| Personal computer | 435 (62.9%) |
| Tablet | 261 (37.7%) |
| Smartphone | 193 (27.9%) |
| Television | 18 (2.6%) |
| Devices-out of online class | |
| Smartphone | 400 (57.8%) |
| Television | 396 (57.2%) |
| Tablet | 312 (45.1%) |
| Personal computer | 220 (31.8%) |
| Eye-screen distance | |
| Under 40 cm | 312 (45%) |
| Over 40 cm | 380 (54%) |
| Ending time for digital devices | |
| Before 20.00 o’clock | 260 (37.6%) |
| Before 22.00 o’clock | 253 (36.6%) |
| After 22.00 o’clock | 179 (25.9%) |
| Luminance | |
| Low | 53 (7.7%) |
| Medium | 600 (86.7%) |
| High | 39 (5.6%) |
| Ambient lightning | |
| Day light | |
| Artificial light | 394 (56.9%) |
| 298 (43.1%) | |
| Usage at dark ambient | |
| No | 345 (49.9%) |
| Sometimes | 313 (45.2%) |
| Often | 34 (4.9%) |
| Spending time in open air (in a week) | |
| None | 91 (13.2%) |
| 1-3 days | 403 (58.2%) |
| 4-5 days | 104 (15.0%) |
| Everyday | 94 (13.6%) |
| Spending time in open air (in a day) | |
| 0-2 h | 519 (75%) |
| 2-4 h | 143 (20.6%) |
| More than 4 h | 30 (4.3%) |