Closed Eyes is a state where the player is playing tennis without his sense of seeing, instead relying on his other sharpened senses to feel the presence of the ball and accurately return it. In this state, the user can hit balls as they come to them, making it extremely difficult for the opponent to predict their next move. Thus, this method allows the user to break through Saiki Kanpatsu no Kiwami.
Nanjiro was the first person in the series to use this technique. In the earlier episodes when Inoe challenged Nanjiro to a match, Nanjiro played with his eyes closed in conjunction with Samurai Zone.
In the manga, Fuji Shusuke played without his vision during his Kantō Finals singles match against Kirihara after he blinded him with a smash. At the time, his Seigaku teammates and Rikkai Dai opponents believed it to be impossible. In his National Finals singles match against Niō Masaharu, Fuji refines and enters his "Closed Eye" state at will, even being able to aim for a cord ball and break all of Tezuka's techniques, including Hyaku Ren Jitoku and Saiki Kanpatsu no Kiwami.
Echizen Ryoma entered this state against Atobe Keigo while using an incomplete Samurai Zone in conjunction as a means to null the effect of World of Ice. Ryoma later entered this state again against Yukimura Seiichi after Ryoma lost his sense of seeing to Yukimura's yips play style.
Fuwa Tetsuhito also used the ability from his own will via blindfold, as he felt that using the Closed Eye was enough to defeat Yukimura.