Quote gypsyanna: Having a friend who lost an eye at age three due to playing with a piece of barbed wire, she only has sight in the other. she is deemed legally blind even though she can function well enough except for not having prospective view. Adam is deemed to suffer tunnel vision which blocks half his vision, but he can see straight ahead which probably explains his ability to get around. Partial site loss is grounds for being legally blind.
They have shown the view through "Adam's eyes" several times. He can see clearly right in front of him but he has no peripheral vision. He may not be able to drive but he can see well enough most of the time to get around, plus he is very observant.