My father who lives out of state has cataracts but insists on driving. He had a minor accident. Coupled with the living conditions my parents have chosen (no heat or running water), I am wondering at what point should I get legal help to protect them from their poor decision-making.
I am not sure what kind of legal help you have in mind. Will they listen to you? Try talking to them. Honestly, the answer to your question depends on how much you love them, and is not found in the law but in your heart.