Don't put her in sorority, give her her own bowl. Use low level aquarium salt at all times if the eye is injured.
What will happen at some point is another girl will come up beside her and flare where she can't see, then be enraged that they're being ignored and attack her.
Betta can see in near darkness, they can actually jump from the water and catch bugs in moonlight. The eye is probably there but damaged, so light on it is painful.