As the name suggests, sun visors are designed to help block the sun and to keep drivers’ eyes from being dazzled. As the Alberta Motor Association website notes, about ninety percent of the information that drivers receive about the road comes through their eyes. Being able to see is essential to safe driving, but the glare of the sun can temporarily blind the occupants of a vehicle. In addition, bright sunlight can cause headaches, fatigue, and other conditions that negatively affect driving. Blocking out some of the light with a sun visor can help reduce these problems.