In a split second, Yuuta's surroundings changed from its usual vibrant colors into a surrounding he was used to— pitch-black. With his sight gone, his senses and feel were both enhanced and all the information he could receive was reduced to the necessary inputs. And since Yuuta needed as much edge as he could during the battle, he didn't need his sight at all since that just distracts him.
Yuuta's hearing also became more sensitive as well that the faintest of sounds causes him to perk up and anticipate something. When he felt a slight wind pressure from his light, he would impulsively click his tongue and avoid the attack coming right at him altogether.
