Sun visors are basically useless. They used to be great for storing CDs in one of those bill fold things. They contain a mirror so you can check your hair, teeth, and eyeballs while you are driving before you wreck and scatter them all over the road. They are useless for blocking the sun rays to your eye sockets. Cars used to have extenders that would allow extra coverage. However, the sun will find a way to fit between your visor and mirror. It’s even better if the sun flickers because of the tree line causing a massive headache, nausea, and motion sickness. Time to invent a transitions windshield.