 This natural history, multi-center, registry study to enroll males diagnosed with X-Linked Retinoschisis and the family members of affected individuals. Onsite affected males will undergo clinical examination and have their blood drawn for genotyping. Onsite unaffected participants will undergo eye examinations. Blood may also be drawn from the onsite unaffected participants but this is not required. Sites outside of NIH are participating as referral centers to accumulate the cohort. Offsite affected male participants will forward a blood sample and records from previous eye examinations to the NEI for review and analysis. Offsite unaffected participants will forward records from previous eye examinations and may provide a blood sample although this is not required. 