The animal kingdom is full of fascinating adaptations, and one of the most intriguing is the ability to sleep with one eye open. While humans drift into deep slumber with both eyes closed, several ...

Have you heard the saying about “sleeping with one eye open”? It’s a bit of metaphoric advice about staying vigilant—and a way to describe very light restless sleep. But sleeping with eyes open is ...

This article is part of our series Battle of the Brands, in which we compare category-leading products to their counterparts to determine which are actually worth your money. Both masks have a soft ...