(plural) spectacles that are darkened or polarized to protect the eyes from the glare of the sun
"he was wearing a pair of mirrored shades"
Tinted glasses worn to protect the eyes from the sun.
"She pulled down her sunglasses before stepping out into the bright afternoon sun."
In plain English: Sunglasses are dark glasses that protect your eyes from bright sunlight.
"She put on her sunglasses to protect her eyes from the bright sun."
Usage: Sunglasses are specifically designed with tinted lenses to shield your eyes from bright sunlight and glare, distinguishing them from regular eyeglasses which lack this protective feature. You should always pair sunglasses with a hat for maximum protection during outdoor activities in strong light conditions.
The word is a straightforward combination of "sun" and "glasses," which was first used to describe eyewear designed specifically for protection against bright sunlight. Its meaning has remained consistent since it entered the English language as a descriptive compound term.