Gojo Satoru wears sunglasses or a blindfold, but it’s not that he can’t see or blind.
Then why does Gojo always cover his eyes? Let me explain the reason!
The general reason why a Jujutsu sorcerer cover its eyes
Some cursed spirits try to attack a Jujutsu sorcerer when they look at each other in the eye. So sorcerers cover their eyes so that they can avoid useless battles. For example, Nanami Kento put on glasses.
But it does NOT apply to Gojo Satoru, according to the explanation in the Jujutsu Kaisen main story. It clearly says “Gojo is exceptional”. The reason isn’t told, but I guess it’s because cursed spirits can sense how strong Gojo is.
Rikugan (six eyes)
Then why Gojo uses a blindfold? What can be considered is that he is saving the power of his Rikugan (six eyes). Though its power is not much explained, there’re many descriptions that Gojo can sense the flow of cursed energy and see through the construction of cursed techniques with his eyes.
It’s hard to think that he can use the eye power without any cost. We can guess that he covers his eyes to reduce the burden on his eyes.
Check the article below too to know more about his Rikugan!