Obstacle Negotiation in Older People With and Without Vision Impairment

Inclusion Criteria: * Age 18 or over * Able to walk independently * Either have normal vision, or impaired vision. * Impaired vision is defined as binocular visual acuity of 20/25 or worse with or without a central scotoma; and/or binocular visual field that is restricted to an average of 100 degrees in diameter or less * Control subjects will have visual acuity of 20/40 or better. Exclusion Criteria: * Not cleared by a medical provider for moderate physical activity * Self-report or have a history of: vestibular disorder or deafness * Medical history of any condition that affects the ability to walk for up to 2 hours with breaks, such as feeling dizzy or faint, chest pain, palpitations, pain or numbness in the legs, shortness of breath, * Cognitive limitations either by self-report or a score on the Mini Mental State Exam below 24 (out of 30) * Walking or gait abnormalities, such as those caused from an injury, surgery, severe arthritis, or neurological condition such as Parkinson's disease * Unable to walk without any walking aids such as a walker, cane, guide dog, or oxygen tank. * Does not speak English