And we’re not talking body temperature.

A UK woman has published a new book, “Cool Shades: The History and Meaning of Sunglasses,” that confirms what fashionistas have known all along: Sunglasses make people look more attractive. Turns out there are actual scientific reasons for this, says author Vanessa Brown, who notes that the dark lenses make faces look more symmetrical because they obscure any asymmetry or unevenness. “They’re also hard and shiny, which gives people the impression that the wearer’s face is more chiseled than it actually is.”

Read more and see images at The Gloss