Shota Aizawa

Aizawa wears an eyepatch because he lost his right eye during the Paranormal Liberation War after being attacked by Shigaraki, a traumatic injury that also cost him his leg, and the eyepatch covers the damage to his eye. His Quirk, Erasure, is eye-based, but he can still use it with his remaining eye, though with limitations.   The Injury Aizawa's right eye was destroyed during the battle against Shigaraki during the Paranormal Liberation War arc.  In the anime, Shigaraki directly clawed his eye out, while in the manga, the decay caused by Shigaraki's quirk affected his eye and the surrounding skin.  Consequences  The injury left him with a permanent scar across his eye and an overall loss of his right eye, which is now covered by the eyepatch. Aizawa also lost his right leg and now uses a prosthetic. Effect on His Quirk Aizawa's Quirk, Erasure, is dependent on his eyes to take effect.  While his eye loss limits his abilities, he can still use the Quirk to a degree with his left eye, which is why he continues to fight as a hero despite the injury.