Why Do Owls Blink One Eye At a Time? (Explained)

by Alex Kountry
Updated on

Owls are interesting birds of prey with special features which sometimes set them apart from other animals and birds. It is possible to have come across the saying one eyed owl.

This is because owls sometimes blink one eye at a time. It might look like a funny thing to do but one of the reasons why they do this is to stay vigilant as owls blink one eye at a time is to stay vigilant at all times as their environment could change within a millisecond.

This article would discuss the reasons owls blinks one eye at a time, what is special about an owls eye, if they close one eye, what it means when an owl looks at you among other things. 

Why Do Owls Blink One Eye At A Time?

Why Do Owls Blink One Eye At a Time

Owls have three separate eyelids for various purposes.

The upper eyelid is what they use for blinking, the lower eyelid closes up when they go to sleep and they also have a third eyelid which is called a nictitating membrane.

Unlike other mammals who close their upper eyelid down when they need to sleep, it is different in owls as the lower eyelids come up for sleep.

This eyelid is used to clean their eyes from debris and also for protection especially during windy flights. 

Because of the way owls eyes are designed, they usually see better in dim light and at night and they are less active during the day.

During the day they prefer to nap, or perch with their eyes closed halfway. 

Sometimes owls can blink one after the other and a major reason for this is security. The owl doesn’t want to be completely blinded for even a second in case of attacks.

This is simply a security measure to keep the bird safe. 

If the owl is also in strong light, it might blink it’s eyes slowing one after the other to rest it eyes from the bright glare.

This alternate blinking allows the left and right sides of its brain to take turns resting. 

Related: Here is an article I wrote on why owls sleep during the day

What Is Special About An Owl’s Eyes?

The eyes of an owl are different from those of other animals and even bird species.

Humans and other animals have spherical eyes which enable us roll and move our eyes around to get a better line of vision.

For owls however, they eyes are shaped like long tubes. These tubes are then fastened with the use of bony sockets called sclerotic rings.

The owl is completely unable to move it’s eyes. They are immobile.

To make up for this, the owl is able to move it’s neck 270° left and right and 90° degrees up and down.

This is quite a special adaptation and it has given the owl a reputation because of the way they look when they turn their heads extensively in either directions. 

Owls also have tapetum lucidum in their eyes which is a mirror like image which reflects light back to the source of light and this cause the owls eye to glow.

This phenomenon is called eyeshine and it is observed in other animals such as cats.

What Does It Mean When Owls Blink?

Blinking usually helps the owls clear the eyes as the nictitating membrane cleaning the debris from their eyes is a form of blinking.

Without being able to do this, the owls eye will become dry and injured.

Owls are not very tolerant of human presence and when you are around them the rate of their blinking can be indicative of their stress levels. 

Some owls can blink their either slowly or rapidly together with staring wide eyes and having small pupils.

This typically means the owl doesn’t want you around and it’s giving you the ‘go away’ blink. 

If you happen to see an owl in daylight and it’s just blinking normally, it is observing you and deciding whether you are a threat or not. If it

Do Owls Close One Eye?

Because owls are nocturnal animals, it is sometimes hard for them to remain in the daylight glare for a long time without closing their eyes.

They prefer to stay in foliage or dim places throughout the day to block out the light. Their pupils are not so great at blocking out the light and sometimes they close their eyes halfway.

The eye of the owls is designed in a way that they have more rod photoreceptors than cones in their retina.

Rods work best in dim light and as such owls are much more suited to night time activities.

Sometimes they might decide to rest one eye and leave the other open. This gives them the opportunity to rest both sides of their brains alternatively. 

Also check out this article on can owls attack a human

What Does It Mean When An Owl Stares At You?

An owl staring at an human can be interpreted in different ways. Most often it probably means nothing and it’s just going about its business or it might even be trying to get you not to startle its prey especially at night. 

It can also be a sign of observation, it might find you intriguing or see you as a danger.

Mostly owls prey on smaller animals and it might just be figuring out how it’ll defend itself if you decide to attack.

This is a selective interpretation and there hasn’t been really much research done into the behaviour of owls. 

Do Owls Recognize Faces?

There is no research to suggest that owls can recognise human faces. Owls generally do not tolerate human touch or presence.

Those who are kept as pets sometimes behave differently when touched by their owners.

Owls are wild animals who should not be kept as pets. New research has shown however that some birds like the crow can recognise human faces and even differentiate between human voices.

That way they are able to recognise their human friends but there is none to suggest the same for owls. 

Do Owls Shed Tears

Owls and other birds have tear ducts and they also have the ability to shed years however they don’t. 

Owls do not cry or shed tears. They can cry if they wanted to but they choose not to, crying is an ability very much possible in birds. 

Research has discovered that birds have tear ducts which secrete watery tears and this serves to protect their eyes.

The researchers also found out that the birds tears had almost the same amounts of electrolytes with those of humans.

However for owls and sea turtles, the researchers discovered higher levels of urea and protein in their tears.

Tears are made up of water and other substances like urea, sodium and protein. 

Tears are quite important in eye health and extensive research has been carried out on mammals but still novel and ongoing in birds.


Owls sometimes blink their eyes one at a time and this is done to protect their eyes from debris.

It is also done regularly as a form of vigilance action. By keeping one eye open, they are able to keep an eye on their surroundings.

Owls have special eyes which are not spherical like most animals but shaped like tubes held in place by sclerotic sockets.

They are unable to move their eyes and they make up for it by being able to move their necks in a wide arch of direction.

This adaptation with their glowing eyes has made owls a subject of mystery and folklore for centuries.

Photo of author

About the author

Alex Kountry

Alex Kountry is the founder of HayFarmGuy and has been a backyard farmer for over 10 years. Since then he has decided to write helpful articles that will help you become a better backyard farmer and know what to do. He also loves to play tennis and read books


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