Table 1.

Demographic and clinical variables of the subjects analyzed in this paper.

	Number	Percent or mean ± SD
Age (years)	961	40.2 ± 10.8
Gender (% female)	431	45.8
Race
African-American	168	17.5
Asian/Pacific Islander	17	1.8
Hispanic	73	7.6
Native American	7	0.7
White	686	71.4
Other	10	1.0
Educational level
Less than high school	35	3.6
High school graduate	147	15.3
Some College	269	28.0
College graduate	218	22.7
Some graduate school	292	30.4
Contact lens wear
None	141	14.7
One eye only	33	3.4
Both eyes	787	81.9
Baseline logMAR visual acuity of the better eye	961	0.08 ± .15
Baseline logMAR visual acuity of the worse eye	961	0.29 ± 0.33
Baseline logMAR visual acuity asymmetry	961	0.24 ± 0.28
Baseline spherical equivalent of the better eye (D)	953	-5.28 ± 4.59
Baseline spherical equivalent of the worse eye (D)	953	-8.01 ± 6.11
Baseline spherical equivalent asymmetry (D)	853	3.26 ± 4.02
Baseline keratometry steep meridian of the better eye (D)	953	48.42 ± 4.42
Baseline keratometry steep meridian of the worse eye (D)	953	52.86 ± 6.06
Baseline keratometry steep meridian asymmetry (D)	953	4.61 ± 4.87