The purpose of this investigation was to determine whether age-related cataract and maculopathy in older siblings predicts development of the same in younger siblings. A population-based study of age-related eye diseases was conducted in 1988–1990 in Beaver Dam, Wisconsin, and a follow-up examination was performed 5 years later. Diagnoses of age-related eye diseases were assigned on the basis of gradings of study photographs. There were 1,088 people from 488 sibships with at least two siblings who could contribute information for these analyses. The authors computed odds ratios and 95% confidence intervals for developing the specific lesion and identifying it 5 years later if an older sibling had it at baseline. The odds ratios were 1.65 (95% confidence interval (CI): 0.91, 2.99) for nuclear cataract, 1.62 (95% CI: 0.92, 2.85) for cortical cataract, 1.95 (95% CI: 0.48, 7.95) for posterior subcapsular cataract, 1.82 (95% CI: 0.91, 3.66) for soft drusen, 8.18 (95% CI: 3.34, 20.08) for retinal pigment epithelium depigmentation, 3.59 (95% CI: 1.71, 7.57) for increased retinal pigment, and 10.32 (95% CI: 0.83, 128.58) for exudative age-related maculopathy. These findings suggest that strong family determinants of lesions of age-related maculopathy are likely, less so for age-related cataract, which confer risk of the same lesion in a younger sibling.