Bright indicator lights ruining your sleep? You're not alone. Here's why they exist

For thousands of years, the nighttime’s daily darkness naturally told humans it was time to go to sleep. Now, it's not always so dark at night.

Bright indicator lights ruining your sleep? You're not alone. Here's why they exist
For thousands of years, the nighttime’s daily darkness naturally told humans it was time to go to sleep. Now, it's not always so dark at night.