Incidence data are lacking for common eye conditions. The authors previously developed a method for estimating incidence from age-specific prevalences for diseases that are irreversible and not associated with differential mortality (Am J Epidemiol 1981;113:606-13). This method is now used to estimate age-specific incidences for senile lens changes, senile cataracts, macular changes, senile macular degeneration, open-angle glaucoma, and diabetic retinopathy. Using age-specific prevalence data from the Framingham Eye Study, five-year incidence rates were estimated for ages 55, 60, 65, 70, and 75. For each condition, estimated incidence increased with age: incidence estimates ranged from 10% to 37% for senile lens changes, from 1% to 15% for senile cataracts, from 3% to 6% for macular changes, from 0.5% to 7% for senile macular degeneration, from 0.2% to 1% for open-angle glaucoma, and, among diabetics, from 3% to 5% for diabetic retinopathy. Standard errors were small for senile lens changes and senile cataracts, but large (of about the same magnitude as the incidence estimates) for macular changes, senile macular degeneration, open-angle glaucoma, and diabetic retinopathy. These estimates may be useful as approximations of the true incidence rates in planning epidemiologic research.