Nictitating membrane

The nictitating membrane, also known as the third eyelid or haw, is a translucent or semi-transparent membrane found in the eyes of some animals, including cats.

In cats, the nictitating membrane is not always visible, as it typically rests beneath the eyelids. However, it may become more noticeable or partially cover the eye in response to illness, injury, or when the cat is experiencing discomfort.

While the presence of the nictitating membrane can be normal, any persistent changes in its appearance or function, such as excessive exposure or inflammation, may indicate an underlying health issue. If you notice unusual eye behavior in your cat, it’s advisable to consult a veterinarian for a thorough examination and appropriate care.