In Phase 1 we continue to examine Orinda Union School District children in grades 1 through 8 (ages 6 through 14 years) annually. The measurement of accommodative response, accommodative lag, phoria, response AC/A ratio, peripheral refractive error, and intraocular pressure will be added to the existing protocol, and photokeratoscopy and two measures of tonic accommodation will be eliminated to minimize respondent burden. Parents of children in the study will be contacted for their permission to release school achievement data (Iowa Test of Basic Skills).