Disclaimer: it all belongs to Kishimoto.
English isn't my first languaje, so I apologize already for any grammatical mistake that you might come across.
The thing is, she hates him.
She hates him so badly and so deeply that sometimes is hard to breathe and Sakura has to remind herself that her diaphragm exists and works and that if she clenches her palms so hard she's going to end up hurting herself with her nails. (And with him is all she ever did)
She does it when Naruto's eyes seem without his light.
She can't even stand to look at him, not anymore. Sometimes she thinks that they'll be fine. But then remembers their hearts breaking and Ino crying after her father died. Remembers Neji's life ending in a throbbing moment, and thinks:
You did this to us.
You broke us.
You were never supposed to leave.
And it's pitiful, because she is his (teammate, friend, old almost sweetheart, never future) but wants him to break apart. She's supposed to heal him. She was always supposed to do that, it was her job. (To take care of the little boy inside of him that was so deeply wounded that he could barely live.)
And now that she has all the skills to do that, to heal him; a part of her, a tiny little part, the one that resented him for making her cry, for dragging them, doesn't want to.
She hates him, but she hates herself even more, because a major part of her, the one that makes her heart beat and her eyes see and makes her care, that part, that part still wants to heal him. Still wants to take Sasuke away from his pain (his loneliness) and tell him that she's there, that she'll always be.
So, one day, when Tsunade finishes fixing his retina, and before he opens his eyes, Sakura takes his hand. "I'm here", she tells him without words.
He knows it, because she never left.
