Table 2. Changes in binocular function after continuous computer gaming for 4 h.
| Binocular function (Expected values)a | Before gaming (a) | After gaming (b) | Following morning (c) | Significance (Post hoc)d |
|---|---|---|---|---|
| NPC (cm) (2.5 ± 2.5) | 7.23 ± 1.64 | 8.77 ± 1.60 | 7.36 ± 1.29 | F = 47.83, p < 0.001(b > a, c) |
| NPA (cm) (NA) | 7.79 ± 1.44 | 9.11 ± 1.93 | 7.78 ± 1.49 | F = 42.50, p < 0.001(b > a, c) |
| Phoria at distance (Δ) (1 ± 1 exophoria) | −0.76 ± 1.71 | −0.83 ± 2.25 | −0.62 ± 1.69 | F = 1.67, p = 0.193 (ns) |
| Phoria at near (Δ) (3 ± 3 exophoria) | −3.73 ± 3.93 | −5.75 ± 4.85 | −3.68 ± 4.86 | F = 18.39, p < 0.001(b > a, c) |
| Accommodative facility (cpm) (10 ± 5) | 14.42 ± 3.20 | 12.68 ± 3.98 | 15.54 ± 2.95 | F = 30.08, p < 0.001(c > a > b) |
| Vergence facility (cpm) (15 ± 3) | 16.94 ± 3.16 | 15.02 ± 3.67 | 17.70 ± 3.41 | F = 38.97, p < 0.001(c > a > b) |
| Blink rate (per minute) (12–19) | 16.24 ± 5.14 | (8.27 ± 5.40)b | (9.51 ± 5.28)c | F = 106.29, p < 0.001(a > b, c) |
Notes.
Data are expressed as means ± standard deviations.
- NPC
- near point of convergence
- NPA
- near point of accommodation
- NA
- not applicable due to the value determined by age or refractive errors
- Δ
- prism diopter
- cpm
- cycles per minute
- ns
- non-significant
a
Expected values from Scheiman & Wick (2002), Weissberg (2004) and Karson et al. (1981).
b
Blink rate after 1 h.
c
Blink rate after 4 h.
d
Bonferroni correction for multiple comparisons.
The p-values were determined using repeated measures analysis of variance. Negative and positive values for phoria represent exophoria and esophoria (horizontal), respectively. Missing data are 15 persons for phoria and 10 persons for blink rate.