Fore! Look Out!
Have you ever been hit with something from behind? Like it came out of nowhere? It was probably really startling. Now imagine that this thing that came out of nowhere were right in front of you. Welcome to the terrifying world of mobility with homonymous hemianopia.
How We See
Our central vision, where acuity is measured, is how we analyze detailed items. The majority of our vision is peripheral vision. Peripheral vision doesn't notice detail. It notices movement and contrast. If that movement and contrast is interesting enough, we may decide to redirect our central vision in that direction to see what's going on. Because a person with homonymous hemianopia has no peripheral vision on one side, there's no awareness of potentially interesting things.
Awareness is Key
The Peli Lens expands the visual field by up to 35 degrees in the blind side, bringing awareness of motion and contrast from the blind side into the seeing side. When walking in areas with an uncontrolled flow of traffic, like a grocery store, a shopping mall, or a park, this awareness helps avoid collisions.