Fig. 6From: Reducing eye fatigue through the use of woodAverages of SSL changes obtained by Eq. (2). Averages of SSL before gaze in Table 1 are shown at the neighborhood of 0.0 SSL of each bar. Standard errors only for plus were shown at the end of each bar. Paired t test results of differences between average SSL changes by item and average SSL of 0.0: *p < 0.05, **p < 0.01. SSL subjective symptoms levelBack to article page