Hi Gayleggg !. What is your diagnosis and what are your cycles and symptoms ?
are you more depressed, hypomanic, manic or a rapid cycler ?
There is no guarantee that this will work for you but .

As I understand it and to simplify it
a lot of Bipolar sufferers are light sensitive

If you are hypomanic you use dark therapy (you need less light and more total darkness)
if you are depressed you use light therapy ( you need more light )

the book explains what to do and more

Fingers 1