15 Peculiar Facts About Dogs That You Probably Didn't Know

3. Dogs Have Three Eyelids

That's right, dogs have an extra eyelid called the 'haw'—a thin, third eyelid that sits in the corner of their eye. This special eyelid serves several important purposes, like helping protect their eyes from dust, debris, and other irritants, while also aiding in keeping their eyes moist by spreading tears evenly across the surface. The haw is visible when a dog yawns or blinks deeply, and though it might seem a little strange to us, it plays a crucial role in maintaining their eye health and keeping them comfortable in their daily lives.