Window coverings that effectively block light are inexpensive and readily available. That solution is superior in every way to any effort through the law to change the neighbor's behavior. The law can punish crimes, but is ill-suited to compelling people to treat each other with kindness and consideration.
Best wishes for an outcome you can accept, and please remember to designate a best answer.
This answer is offered as a public service for general information only and may not be relied upon as legal advice.