Poor Rey had to have some eye surgery. One of her eyes looked up and down while the other eye looked side to side. It may look cosmetic, and she is not so vain to require cosmetic surgery, but it was affecting her depth perception. She needs that to properly use her weapons.
Unfortunately, since she was not willing to sell the droid, she could not afford to go to the top of the class specialist.
She had to make do with the village quack and take her chances.