Table 3.

The safety index and the efficacy index for the entire sample.

	Younger group			Older group			t-test p-value
	N	Range (min to max)	Mean (± SD)	N	Range (min to max)	Mean (± SD)
Post-LASIK
Safety index	341	0.75 to 1.58	1.03 (± 0.12)	341	0.56 to 1.60	1.01 (± 0.13)	0.204
Efficacy index	341	0.34 to 1.43	0.97 (± 0.16)	341	0.32 to 1.56	0.91 (± 0.19)	0.000

SD standard deviation, N number of participants.

Significant values are in bold.