Clinical Trial of Peripheral Prism Glasses for Hemianopia

Inclusion Criteria: * At least 18 years of age. * Sighted in both eyes, with monocular visual acuity (best corrected vision), of at least 20/50 in each eye. * Complete homonymous hemianopia of more than 3 months duration * Refractive error within the -5 dioptre to +5 dioptre range * No significant cognitive impairment * No history of wearing the Peli system of peripheral prisms for hemianopic field expansion (patients who have worn another type of prismatic correction for hemianopia such as yoked prisms or the Gottlieb VAS system can participate in the study) * No physical or mental disabilities, including cognitive dysfunction, balance problems or other deficits that could impair ability to walk or use the peripheral prism spectacles. * Able to walk (using a cane or walker is OK) or control the movements of their own wheelchair. * In sufficiently good health to attend four in-office visits. Exclusion Criteria: * Diagnosis of dementia * Diagnosis of visual neglect * History of seizures in the last 6 months * Incomplete hemianopia