We analyzed and compared the visual accommodation of kindergarten children who were gazing fixedly at images from three different sources: Nintendo Game Boy DMG-01(TM) (non-backlit type game console: NBGC), NEC PC EnginePI-TG6(TM) (color backlit-type game console: CBGC) and a cartoon drawing (drawing). Subjects for the experiment were 13 4- to 5-year-old kindergarten children. The contrast ratios were, in the order, 1.1 (NBGC), 3.1 (drawing), and 3.4 (CBGC). These values show that the contrast of the NBGC screen was considerably lower than the others. The mean accommodative power increased when looking at all three types of image: a drawing (1.75±0.52 D; mean±S.D.), CBGC (1.82±0.61 D), and NBGC (2.26±0.50 D). Compared with the other 2 targets, NBGC required stronger accommodation, indicating that the legibility of the NBGC was poor. Repeated measures ANOVA was used for the values of accommodation for each type of target. There were significant differences among the 3 targets (p<0.01). Significant differences were seen between NBGC and drawings (p<0.01) and NBGC and CBGC (p<0.05) using paired Scheffe test, but not between CBGC and drawings. This supports the finding that the legibility of NBGC is low due to dark and low contrast screens with poor resolution.

The effects of presentation speed and both positive and negative CRT (cathode ray tube) displays on pupil size were studied. The pupillary areas of 12 female student volunteers were measured by infrared videopupillography. The three presentation speeds were no change for 12 sec., a change every 2 sec. for 12 sec., and a change every 1/2 sec. for 12 sec. Two-way analysis of variance showed that the pupil size in the negative displays was significantly larger than that in the positive displays. A difference in pupillary area results from different display speeds, irrespective of a difference in polarity.

We analyzed and compared the visual accommodation of kindergarten children who were gazing fixedly at images from three different sources: Nintendo Game Boy DMG-01 TM (non-backlit type game console: NBGC), NEC PC EnginePI-TG6TM (color backlit-type game console: CBGC) and a cartoon drawing (drawing). Subjects for the experiment were 13 4-to 5-year-old kindergarten children. The contrast ratios were, in the order, 1.1 (NBGC), 3.1 (drawing), and 3.4 (CBGC). These values show that the contrast of the NBGC screen was considerably lower than the others. The mean accommodative power incresed when looking at all three types of image: a drawing (1.75H0.52 D; meanHS.D.), CBGC (1.82H0.61 D), and NBGC (2.26H0.50 D). Compared with the other 2 targets, NBGC required stronger accommodation, indicating that the legibility of the NBGC was poor. Repeated measures ANOVA was used for the values of accommodation for each type of target. There were significant differences among the 3 targets (p<0.01). Significant differences were seen between NBGC and drawings (p<0.01) and NBGC and CBGC (p<0.05) using paired Scheffe test, but not between CBGC and drawings. This supports the finding that the legibility of NBGC is low due to dark and low contrast screens with poor resolution.