Hello and thank you for the opportunity to assist you. My name is ***** ***** I will do my very best to answer your legal questions.
From a legal perspective, your recourse depends on the specific facts of the situation.
First and foremost, you would have to sue your neighbor. This can be problematic because even if you were to win the lawsuit, you would have to spend quite a bit of money on legal fees, and you would clearly destroy any relationship you have with the neighbor. That could make things so uncomfortable, that you will wish that you had simply moved in the first place.
Second, if you do opt to sue your neighbor, a court would have to weigh the rights of your neighbor to use her property as she sees fit, against your rights to enjoy your property without disturbance. So, the bot***** *****ne is that the outcome in court would depend upon the reasonableness of the situation. Is your neighbor's light unreasonably bright and unreasonably aimed at your house, or are you being unseasonable by demanding total darkness? Moreover, can this be easily remedied by you installing curtains or blinds?
Obviously I do not know the answers to those questions, but that is what a court would examine in a lawsuit. Since you would be the plaintiff, the burden of proof would be on you. You would have to prove that your neighbor's light is a nuisance, and that you are not being unreasonable. In a worst-case scenario, if this were to end up going all the way to trial, I would expect that you would have to pay between $10,000 and $20,000 in fees associated with the lawsuit. Because of that, moving may be the best answer if you cannot fix this short of going to court.
Does that answer your question? Please let me know if you need clarification, as I am happy to continue helping you until you are satisfied.