What is the purpose of the third eyelid in rabbits?

The correct purpose of the third eyelid in rabbits is to help lubricate the eye continuously. This unique structure, also known as the nictitating membrane, plays a vital role in maintaining eye health. It helps spread tear film across the surface of the eye, providing moisture and nutrients while also protecting it from debris and injury.

By continuously moistening the eye, the third eyelid reduces the risk of dryness and irritation, ensuring clear vision and overall eye comfort. This is particularly important for rabbits, as they are prey animals and rely heavily on their vision to detect threats in their environment.

While protecting the cornea during a dust storm is important for eye health, the specific function of the third eyelid is more about continuous lubrication than just protection during specific events like dust storms. Therefore, the primary role focuses on keeping the eyes moist and healthy at all times, enhancing the rabbit's ability to navigate its surroundings safely.