Sleep-inducing blackout curtains

I have mild insomnia that occurs about once or twice a month. It can be managed with sleeping pills, but I prefer not to use medication whenever possible to prevent dependence. I have seen many people around me become addicted to drugs while trying to cure simple insomnia. I use blackout curtains to promote sleep, and they are quite effective. Sometimes, it takes about ten minutes to fall asleep after closing the blackout curtains.It doesn't get caught.