Initial cross-sectional results from the Orinda Longitudinal Study of Myopia.

BACKGROUND

Although investigations of human refractive error development and normal ocular growth have been conducted for the last 50 years, no previous study of refractive error and the ocular components has measured all the ocular components.

METHODS

The Orinda Longitudinal Study of Myopia was initiated to characterize the development of refractive error and normal eye growth in a sample of predominantly Caucasian children ages 6 to 14 years.

RESULTS

Cross-sectional results from 530 children ages 5 to 12 years in the 1st, 3rd, and 6th grades are presented.

CONCLUSIONS

This sample's refractive error decreased toward emmetropia with age from an average of +0.73 D at age 6 years to an average of +0.50 D by age 12 years. Between the ages of 6 and 12 years, the vitreous chamber elongated (by 0.52 mm) and the crystalline lens power decreased (by 1.35 D); surprisingly, the crystalline lens thinned by 0.14 mm during this same time period.