Prevalence of refractive errors in adults over 40: a survey of 8102 eyes

The prevalence of refractive errors was studied in an adult rural population. Of the 8102 eyes studied 18-4% were myopic, 57-1% were emmetropic, and 24-5% were hypermetropic. Mild myopia was commoner in males than in females, and mild hypermetropia was commoner in females than in males. There was increasing hypermetropia with increasing age, probably due to unmasked, latent hypermetropia up to the age of 70 years and to a true shift toward hypermetropia after the age of 70 years.