Imagine a bright light shining in your eyes all night long, that's what happens when you're exposed to too much light at night.
This study found that too much light at night can make it harder for your brain to work properly, which could lead to a problem called Alzheimer's disease.
To help your brain stay healthy, try to make your room dark when you go to sleep and use a dimmer switch to make the lights in your home less bright.
Just like you need to eat healthy food and exercise to be healthy, your brain needs darkness to rest and recover each night.
