We are all aware that owls have particularly spectacular eyes, I don’t think anybody can disagree with that fact. Not only do they look captivating but they also amaze us with the extreme level of skill needed by mother nature to craft something so brilliant at doing what eyes do best – see. These large round eyes allow the owl to be precise, efficient and stealthy when they hunt, especially at night. In fact owls eyes aren’t typical eyeballs at all, they are actually considered to be more tube-like. These tubes are surrounded by the Sclerotic ring, which is basically the bones within the owls skull. Since the eyes are locked in place, they cant actually move their eyes like we can. Since they don’t have a ‘ball‘ the eyes cannot roll from side to side – makes sense right when you think about it like that? The tubes make sure the eyes are locked still. Luckily for owls, their ability to turn their heads 270 degrees means they don’t miss anything with their lack of rotating eyeball.
So after providing you with a brief overview of the owls eye capabilities, I will turn to the main question being asked in this article and that is…
Can an owl blink?
And the answer to this is… yes, they can and they do, with their 3 eyelids! If an owl didn’t blink then their eyes would dry up and become damaged by injury as they come in constant contact with the world and its elements.
Birds in general tend to have more than one eyelid so they can use one for sleeping and the other for cleaning the eye, at the least. But an owl actually has 3 eyelids and to keep it simple at this point I will sum up these three eyelids as doing their most basic task:
Upper Eyelid – Blinking
Lower Eyelid – Sleeping
Inner Eyelid (Nictitating Membrane) – Cleaning their eyetubes
The owls upper eyelid closes downwards, like our human eyelids do. Most bird species eyelids close by the bottom lid closing up so an owls upper eyelid works slightly differently. This eyelid is also sometimes referred to as the ‘true eyelid` and in most birds this will only be used for sleeping whereas owls also use this eyelid when they blink.
The lower eyelid is simple, it closes up when the owl sleeps and this is used just for rest.
The inner eyelid, also known as the nictitating membrane is a translucent eyelid which moves horizontally rather than vertically (sometimes it is argued it moves more diagonally). This eyelid comes from the inner corner of the owl’s eyes across to the outer corner and this is used like a window wiper effect to clean the eye. This eyelid is also useful when the owls are hunting, if they are mid-hunt yet need to protect their eyes from injury and damage they can use this eyelid for protection but can still see their prey because this eyelid is translucent. This eyelid helps protect the eye from wind, prey, dust, water, sharp carcasses and any extreme weather. A fun fact is that reptiles, some mammals and even sharks also have a nictitating membrane!
In conclusion, it seems like there really are endless things to learn when it comes to the wonders of our owls. These beautiful creatures never fail to amaze us with their interesting and highly developed anatomy making these creatures the highly skilled hunters we watch in awe.