A “haw” (also known as a “nicotating membrane”) is often called a “third eyelid.”It’s on the inside corner of a dog’s eye and serves to prevent foreign objects from injuring the eye. In most breeds, one hardly notices the haw, but in some breeds like the Basset Hound, Bloodhound and Otterhound, it’s noticeable.
Basset Hound by Rachel Parker –rachelsstudio