A fully sighted person has about 300 degrees of awareness in the car. They’re aware of what is in front of them, and they have mirrors to bring awareness of the areas behind them where they cannot see. These mirrors are all conveniently placed to give a person with full visual field 300 degrees of awareness. Now what if you have homonymous hemianopia? If you have right hemianopia, your rearview mirror and passenger side mirror are both outside of your awareness. And if you have left hemianopia, your driver’s side mirror is outside of your awareness. While peripheral prisms can help, the goal should be to get as much of that 300 degree awareness as possible. Outfitting a car with auxiliary mirrors is very important for drivers with visual field loss.
