The Effects of Chewing Gum in Preventing Eyestrain

Table 1

Reproducibility of the values before chewing gum or tablet candy (carryover effect).

Outcomes	Number of data	Difference of mean value before chewing sample	SD	95% confidence interval		value
		(gum-tablet candy)		Lower limit	Upper limit
Subjective accommodation (D)	92	-0.03	0.97	-0.23	0.17	0.786
Spherical equivalent refraction (D)		-0.03	0.29	-0.09	0.03	0.393
Ring break-up time (sec)		-0.04	3.31	-0.73	0.64	0.903

SD: standard deviation. Paired t-test.