Nictitating membrane - Wikipedia It is often called a third eyelid or haw, and may be referred to in scientific terminology as the plica semilunaris, membrana nictitans, or palpebra tertia Unlike the upper and lower eyelids, the nictitating membrane moves horizontally across the eyeball
Cherry Eye in Dogs and Cats - Veterinary Partner - VIN The third eyelid, called the nictitans or nictitating membrane, arises from the inner corner of the eye and covers the eye diagonally as shown Its purpose is to further add moisture and protect the eye
Nictitating Membrane - an overview | ScienceDirect Topics The nictitans gland in small animals is an important accessory tear-producing gland providing about 25–40% of the total tears Lymphoid follicles are usually present on the posterior or bulbar surface of the nictitans, appearing as raised translucent spots, and especially prominent in the horse
Third eyelid gland prolapse (“cherry eye”) - Animal Vision Care . . . Prolapsed gland of the third eyelid (nictitans) is often referred to as “cherry eye ” The gland is actually one of two tear glands positioned around each eye in dogs and cats The prolapse occurs due to a weakness of the connective tissues that hold the gland in place
What is a Nictitating Membrane? - Spiegato Many animals have a third eyelid called a nictitating membrane This clear eyelid can be drawn across the eyeball for protection from debris, prey, or the dryness of air, similarly to regular eyelids Reptiles, birds, sharks, and some mammals evolved this extra layer of protection to keep their eyes moist and clean while maintaining visibility
NICTITATING MEMBRANE Definition Meaning - Merriam-Webster The meaning of NICTITATING MEMBRANE is a thin membrane found in many vertebrates at the inner angle or beneath the lower lid of the eye and capable of extending across the eyeball
Nictitans Gland Protrusion (cherry eye) | Vet Vision, Inc. The third eyelid (membrana nictitans) lies between the eyelids and the eyeball at the inside corner of each eye Its purpose is to protect the eye and to help contain and spread tears over the cornea