An eyeshield is a piece of football

American football

American football is a sport played between two teams of eleven with the objective of scoring points by advancing the ball into the opposing team's end zone. Known in the United States simply as football, it may also be referred to informally as gridiron football. The ball can be advanced by...

 equipment. It is a visor that attaches to the helmet

Football helmet

A football helmet is a protective device used primarily in American football and Canadian football. It consists of a hard plastic top with thick padding on the inside, a face mask made of one or more plastic bars, and a chinstrap. Some players add polycarbonate visors to their helmets, which are...

 of a player to protect the eyes. It leaves the mouth exposed and covers the eyes and nose. Only clear eyeshields are allowed in high school football. On the college level

College football

College football refers to American football played by teams of student athletes fielded by American universities, colleges, and military academies, or Canadian football played by teams of student athletes fielded by Canadian universities...

, a clear eyeshield may be used if the player has eye problems. The NFL

National Football League

The National Football League is the highest level of professional American football in the United States, and is considered the top professional American football league in the world. It was formed by eleven teams in 1920 as the American Professional Football Association, with the league changing...

requires a waiver by the trainer and a doctor to wear tinted or reflective visors.