By Lisa Mulcahy November 27, 2022 at 7:26 a.m. EST If you’ve ever had your vision “white out” (or “gray out”), you’ve probably felt a little unnerved by the experience. “You’ll see a bright light, and your vision will go pale,” says Teri K. Geist, a trustee of the American Optometry Association. As disconcerting as they...