The research will consist of a large cluster-randomized trial in which all clusters receive visual acuity screening during a baseline census, and then half subsequently receive screening with OCT, fundus photography, and intraocular pressure testing with an iCare tonometer. Participants with abnormal results will be referred to the local eye hospital for examination and treatment. Repeat visual acuity assessment will be performed 9 years later. Those with visual impairment at the time of the final census, defined as visual acuity worse than Snellen 20/60 (Metric Snellen worse than 6/18; logMAR worse than 0.48), will receive a comprehensive eye exam to determine the cause of visual impairment.
Specific Aim 1 - Visual Acuity: To determine whether an intensive screening program results in better visual acuity at 9 years than screening with visual acuity testing alone. The investigators hypothesize that individuals from clusters randomized to the intensive screening program will have better visual acuity compared to those receiving visual acuity testing alone.
Specific Aim 2 - Eye Disease: To determine whether an intensive screening program reduces the incidence of visual impairment due to AMD, DR, or glaucoma. The investigators hypothesize that incident visual impairment due to AMD, DR, or glaucoma will be less common in clusters randomized to the intensive screening program.
