Figure 1.

Examples of raw J0 data from six subjects. To estimate change in astigmatism with age, individual regression equations were generated based on each subject's longitudinal data. Slope values represent change per year. Analyses of longitudinal change in refractive error were conducted using slope values from each subject's regression data for each component of refractive error (refractive astigmatism, keratometric astigmatism, internal astigmatism, spherical equivalent). RA in regression equations represents refractive astigmatism.