I feel like a lot of people didnt understand the movie. When youre blind you picture whats around you in your head, and you use your imagination..thats why when it was from her point of view,such as the pool scene would all of a sudden be a vast ocean.
She had surgery-literally everything she pictured in her head and lived like is completely different. She never judged it and was just experiencing it. She even wasnt dissapointed with what he looked like and still chose to be with him. Seeing colors, roads,shadows, the room, the city, sex from other perspectives, playing with the way we dress ourselves how you look makeup clothing hair color..she never got to do these things before.

The husband would pretend to not be there when she was blind so she would be worried.. He liked her being under his thumb. he watched videos of her over and over to feel in control. he faked a break in and stole the dog because he was jealous. he tampered with her eye drops so she would loose her vision again. she did sleep with another guy but she never experienced being attracted to someone physically before, if you recall the 2 other times she tried to have sex with her husband he couldnt handle it because he, once again, wasnt in control.

When the doctor told her they were tampered with she gained her vision back taking the correct ones and pretended to still be blind... reason maybe because it was scary finding this out or she wanted to know more about how he really was, maybe she still cared about him and wasnt ready to leave him. When she realised he didn't leave the house and was watching her and then finding the letter from assumably a kid in their previous apartment about him stealing the dog, i think that was her confirmation of it being over (because lets be real, thats messed up).
He found the empty bottles and realised shes been continuing taking eye drops.. So at the concert she looks him in the eye while singing showing him she sees what he's done and she's not blind anymore.

The ending after that I'm not 100% sure.. did he pass away? Did she ever get a hold of her babys dad? Who knows. I guess its more about her continuing her life independently?

There was art element to it that maybe some parts had more meaning that I'm unaware of, like the carcass the kid came across or the naked husband covered in blood. but overall it made sense. Could it have been more clear for the audience? maybe yes it would be loved more and have a stronger ending if we had more understanding, but not all movies are like that