Blue light is a high-energy part of visible light from the sun, screens, and light-emitting diode (LED) bulbs. Your cornea and lens don’t block blue light the way they block ultraviolet (UV) rays.

Our smartphones, computer screens, televisions, the fluorescent lights in the office, and the sun all emit blue light. And experts want you to know that yes, exposure to blue light does affect sleep.

If you’re like most adults, you may be spending more time in front of screens than ever before — and feeling eye strain as a result. To help ease this strain, many people have turned to blue light ...