If she's fine outside at night you may want to consider having a vet check her eyes for a cause of light sensitivity. If you have an overcast day, without raining to deter the dog, and she will go out then it definately could be a light sensitivity problem. She could have an ulcer in the eye or something like that. Canine distemper also can present with sensitivity to light although if she is vaccinated and it is the only symptom she has then I'd be doubtful of that.

Health problems ruled out you're going to have to take her out on a leash with some irresistable treats like diced hot dog and get her mind on doing some commands for a few minutes at a time outside or if she isn't trained to a lot of commands (because some people don't train their dogs to do tricks) you can simply toss the little treats so she can see them one at a time and get her mind on finding the treats rather than worrying about getting inside. Make sure her time out there is full of praise and good things.