Do Birds Have Eyelids? (Complete Guide)

Of all the senses a bird has, vision is arguably the most important, relying almost exclusively on it to find food, attract mates and protect from predators. Therefore, the bird’s eye is a highly developed and complex organ, and the related anatomical features also play a vital role in the bird’s vision and overall survival.

Read on as we explore whether birds have eyelids, eyelashes, and even tear ducts, and what these structures are used for. So let’s get started, do birds have eyelids?

All birds have three eyelids: an upper eyelid and a lower eyelid, with a third “eyelid” below to protect the cornea. This translucent layer of tissue, called the nictitating membrane, slides over the eyeball and lubricates the eye, keeping dust particles out.

The nictitating membrane retracts horizontally across the eye, allowing birds to continue seeing where vision would be impaired without putting them at risk of predation, even with momentary eye closure and loss of vigilance.

But do all birds share this particular anatomical trait? Does it have any other functions? Read on to learn more about how birds’ eyelids allow them to survive.

Close-up of the protective blinking (third eyelid) membrane of an adult wild Sandhill Crane

Can a bird close its eyes?

Birds can close their eyes, and often (but not always) do so while sleeping. The bird’s lower eyelid moves up to meet the upper eyelid, blocking light and allowing the bird to rest.

Can birds see through their eyelids?

Birds have a third translucent membrane, similar to an extra eyelid, that retracts horizontally across the eyeball, allowing the bird to temporarily close its eyes while maintaining vision.

This “nictitating membrane” allows waterfowl to see underwater, raptors to catch prey without injuring the surface of the eye, and birds to continue to safely navigate dusty air or heavily polluted environments.

A bald eagle with its eyelids closed during a storm

Do all birds have eyelids?

All birds have three eyelids. Two of them are external, an upper cover and a lower cover, where the lower cover is more removable than the upper cover.

Birds, as well as reptiles and some mammalian species, are equipped with what is known as the “third eyelid,” also known as the nictitating membrane. This stretchy thin layer sweeps across the eyeball horizontally, providing protection from harmful airborne particles and providing lubrication and cleansing.

This nictitating membrane also protects the eyes of birds of prey from injury while hunting, and enables diving ducks to open their eyes and see underwater without any impurities entering the eyes and impairing vision.

Do birds blink?

Most birds don’t blink in the traditional way that humans do with the rapid opening and closing of their eyes. Blinking birds — owls, ostriches and parrots — are in the minority.

Unlike humans’ traditional blinking, most birds rely on the third eyelid to quickly clear the eye, rather than temporarily closing the upper eyelid with the eyeball.

Parrots are one of the birds that blink like humans

How Do Birds Blink?

Only parrots, ostriches, owls, and a handful of other species blink by closing the upper or lower outer eyelids. Owls blink by closing their upper eyelids downward.

For most birds, the nictitating membrane serves the same purpose as blinking, a quick blink and horizontal retraction on the eyeball to moisten the eye and remove any dirt particles that may have entered the corneal surface.

Do birds close their eyes when they sleep?

Birds generally close their eyes completely when they close their eyes, and also often tuck their heads and beaks under their wings when resting. This is the most effective and relaxing way to restore energy reserves.

To stay alert overnight, some birds, including many ducks, actually sleep with one eye open and the other closed.This phenomenon, known as monohemispheric slow wave sleep (USWS), have them keep one part of their brain alert to danger while the other part shuts down and rests.

Some flying birds, including swifts, sleep on their wings and keep one eye open at all times. This ensures they are aware of their surroundings and alert to the presence of any predators.

Pygmy owl, sleeping on a branch

Do birds have eyelashes?

Some birds, including hornbills, secretary birds, certain parrot species, ostriches, and vultures, have eyelash-like hairlike feathers around their eyes.

These tiny, bristly feathers serve the same purpose as human eyelashes, protecting the eyeball from damage by triggering a reflex action that closes the eyelid when touched.

Do birds have tear ducts?

The lubricating duct is part of the nictitating membrane in birds and serves the same function as the tear duct in humans and many other mammals. However, birds do not cry or shed tears out of grief, the lubricating tube is used purely for cleaning purposes to keep the corneal surface moist and free of dirt particles.

Blinking eyelid membrane of the common grouper

Do pigeons have eyelids?

Like other birds, pigeons have upper and lower eyelids, as well as a third inner membrane that protects and lubricates the eyeball.

Do owls have two eyelids?

Like other birds, owls actually have three eyelids, not two. They have an upper eyelid that closes downward when the owl blinks. When owls sleep, their lower eyelids close upwards.

The owl’s third eyelid is the so-called nictitating membrane, a protective layer that slides diagonally across the cornea, keeping dust, grit and dirt particles from entering and impairing its vision, while also cleaning and lubricating the eyeball. In owls, this nictitating membrane is opaque rather than translucent.

Owls have three eyelids, just like other birds

Do all birds have three eyelids?

All birds have upper and lower eyelids, as well as a nictitating membrane, often called the third eyelid. This is a translucent inner layer that lies under the upper and lower eyelids and sweeps horizontally or diagonally across the bird’s eyeball. It acts to cleanse and protect the eyeballs.