blue light

[bloo lahyt]

noun

1. a band of the visible light spectrum that has a shorter wavelength and produces higher energy than other colors of light: occurring in sunlight and emitted by electronic devices that use LED technology.

2. American History, Usually Disparaging.,  Also Blue Light a member of a faction of the American Federalist party considered disloyal for opposing the War of 1812: so called from the claim that they flashed blue light signals to alert the British to the presence of blockade runners.

Word History and Origins

Origin of blue light¹

First recorded in 1810–15

Example Sentences

She adds that teens "still need lots of sleep", which can be disrupted by overnight notifications or late-night exposure to blue light through smartphone screens.

From BBC

Humor is derived from individual perception, and it’s hard to see much of the world stuck in the blinding blue light of a digital silo.

From Salon

Too many of us wake up and consume blue light before sunlight, fumbling in the dark for a smartphone or a tablet to see what fresh Hell the push notifications have in store for us today.

From Salon

They gaze in wonder as the bottom of the ship opens up, revealing a warm blue light.

From Los Angeles Times

And while some studies have suggested blue light - such as that emitted by screens - makes it harder to drift off because it suppresses the hormone melatonin, a 2024 review of 11 studies from around the world found no overall evidence that screen light in the hour before bed makes it more difficult to sleep.

From BBC