OHTS Phase 3 will re-examine study participants 20 plus years after enrollment to document clinical status and the incidence and severity of self-reported functional limitations. The 279 participants who developed POAG in OHTS Phase 1 or 2 will have more than 10 years of post-POAG follow-up by Phase 3. The timing of re-examination at 20 years is meaningful because 20 years approaches the median life expectancy of OHT patients in their 60's and 70's and half the median life expectancy of patients in their 40's and 50's. For the first time, patients with ocular hypertension and clinicians will have high quality data about the long-term risk of developing POAG and functional limitations associated with the disease. These data will facilitate patient-centered care so that patients and clinicians can decide on the appropriate frequency of tests and examinations and the potential benefit of preventative treatment.