PHILADELPHIA (WPVI) --you may not think the light from a street lamp can affect your overall sleep.
But experts are starting to think it can.
researchers at Stanford University surveyed 15-thousand Americans about the quality of their sleep.
Then they used satellite information to see how much light everyone is exposed to.
They found those in light-intense areas such as cities reported going to bed later, sleeping fewer hours and feeling sleepier during the day than people who are not exposed to much light.
More studies are needed but for now many experts are recommending using black-out shades or thick curtains to help darken your room and improve your sleep.
By the way, adults should get 7 to 9 hours of sleep each night.