Table 1

The mean differences in ln(P_dc) between the two levels of each categorical variable estimated by fitting a two factor fixed effects models to the fellow eye differences in ln(P_dc). p Values were estimated using two sided t tests

	Mean difference	95% CI	p Value
Lens − no lens	0.341	0.063, 0.169	0.02
Right − left	−0.013	−0.265, 0.290	0.93
First − second	−0.127	−0.405, 0.151	0.36