• Inclusion/Exclusion Criteria Inclusion criteria - Common  At least 14 years of age (no upper age limit) In sufficiently good health to be able to complete sessions lasting 2-3 hours Able to understand English Able to give voluntary, informed consent Able to independently move short distances Binocular vision parameters within normal limits (Stereopsis ≤ 100 arc sec on any stereo test)  Inclusion criteria - subjects with visual field loss  Visual field loss, either peripheral field loss (<30 degrees diameter) or hemianopic field loss (blind in half of visual field) Better than 20/100 visual acuity in the worse eye  Inclusion criteria - subjects with normal vision  No restrictions of the peripheral visual field: (> 60 degrees diameter) Better than 20/40 visual acuity in the worse eye