__By Ron Kaspriske
2. They help you stay relaxed. Prolonged squinting can increase tension. Anytime a muscle group stays in a contracted state for long periods, it tends to have a contagious affect on other muscles. You'll find yourself gripping the club tighter and possibly restricting your body turn. Don't think so? Think about how hard you grip a chair when a dentist starts working on your teeth.
Ron Kaspriske is the fitness editor of Golf Digest.
(Photo by Getty Images)