User can make people unable to see.

Pros:
-user can control blindness of target
-user can guide who they blind
-user will not be physically impaired when using quirk
-user can stop villains or people who aim to hurt others

Cons:
-user will have horrible sight when nor using quirk
-user will get dry eye if quirk is used for too long
-user will have trouble sleeping
-user may have dreams about what targets experience when blind

Weakness: mental blocks
User can't make a target blind if they have strong mental blocks, users will gets a headache from this.