The investigators are developing a new test of pedestrian hazard detection in virtual reality (VR) head-mounted display (HMD) headset, which shows virtual oncoming pedestrians in 3D while subjects are walking in real-world environment, for evaluation of visual field expansion to improve mobility in people with visual field loss.

The investigators will develop a new pedestrian hazard detection test and conduct a single arm interventional clinical trial to evaluate simulated low vision assistive devices in a sample of field loss subjects. Pedestrian detection performance with and without field expansion information will be tested and compared. The study will include 1 to 4 visits (each 2 to 4 hours) depending on the number of trials and experimental conditions (e.g., with and without simulated assistive devices) the subject is comfortable completing. The time between visits may vary depending on scheduling constraints and availability. During each visit, the subject will complete a series of simulated collision avoidance trials in VR requiring the detection and natural avoidance of a colliding pedestrian (alongside non-colliding pedestrians) while physically walking through an empty corridor. The study will be considered minimal-risk since there will be no physical obstacles that present actual collision risks.

Inclusion criteria:

• 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)
• 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

Exclusion criteria:

• Patients with any self-reported physical or mental disabilities, including cognitive dysfunction, balance problems, or other deficits that could impair their ability to respond to the stimuli presented in this study
• Any person with a self-reported medical history (such as pacemaker use or photosensitive epilepsy) or physical condition listed on the device manual of the Oculus / HMD system used for the experiment as a contraindication
• Any self-reported history of seizures (any type) in the last 6 months