Parrots have eyes that sit flat against the sides of their heads, making it difficult to see them, let alone when they blink. Eyelids are essential for keeping the eyes moist and dust and other harmful particles out.
Parrots have an upper eyelid, lower eyelid, and a nictating membrane (third eyelid). The nictitating membrane is a translucent layer covering the entire eye, enabling birds to keep their eyes moist and the cornea protected from damage while still seeing perfectly.
The nictitating membrane is a thin, clear layer. So, it’s hard to tell when a parrot blinks. If a parrot’s sleeping, it’ll do so with one eye open, only closing both eyes when fully at ease. Like the nictitating membrane, parrots’ ability to sleep with one eye open is an evolutionary survival tool.
Smaller parrots blink with their nictitating membrane so rapidly that the human eye can’t see it.
Bigger parrots can often blink with their top and bottom eyelids halfway or fully closed. Even though they seem to only be moving their two eyelids, they primarily use their nictitating membrane.
There may be a slight movement of the top and bottom eyelids when blinking because the nictitating membrane is connected to the lower eyelid. This moves along with the nictating membrane.
It’s difficult to detect the third eyelid when parrots blink due to its transparency and how quickly it slides over the cornea. Usually, humans can only see this with slow-motion footage.
However, there are times when a parrot will blink very slowly at you.
Parrots will slowly blink to display:
Blink at your parrot slowly. If your parrot slow-blinks back, it trusts you completely.
Why Do Parrots Have Eyelids?
Parrots have eyelids for two purposes:
- Protection from particles that could harm its eyes.
- Lubricate the eyes so that they remain moist.
Parrots’ eyelids protect their corneas and enable them to watch out for predators. According to Slatter’s Fundamentals of Veterinary Ophthalmology, parrots can use their third eyelid voluntarily.
Parrots use their nictating membrane in the following situations:
When parrots blink, they use their third eyelid only. While the lower and upper eyelids move up and down, the nictitating membrane sweeps across the eye horizontally.
The nictating membrane is thin and nearly transparent, allowing them to see even while it runs across the entire eye. So, parrots can protect and lubricate their eyes while being aware of their surroundings.
Feeding Their Young
Baby chicks are blind during the first few days of their lives, so they can’t see where the food is and may accidentally poke a parent in the eye.
Parrots use the nictitating membrane to protect their corneas from the beaks and claws of their offspring.
Protection During Flight
When flying, parrots must protect their eyes from debris and bugs.
With the nictitating membrane, parrots don’t need to worry about something getting in their eyes. This third eyelid keeps their eyes from drying out and impairing their vision while flying.
Parrots may rapidly move their nictitating membrane when feeling threatened. This will keep their eyes moisturized while they focus on the threat.
They’ll blink with their nictitating membrane when bobbing their heads up and down. This enables them to control any motion blur and prevent dizziness.
Do Parrots Close Their Eyes?
Parrots rarely close their two main eyelids. Since they’re so thick, a parrot can’t see through them.
This momentary blindness makes a parrot vulnerable to threats and ambushes from predators. So, parrots use their third eyelid to maintain the health of their vision while leaving their large eyelids open.
These thicker eyelids are usually reserved for greater dangers to the eye. For example, a parrot might close its two eyelids when it sees a projectile coming. These eyelids protect the cornea from harm.
Do Parrots Sleep with Their Eyes Open?
Parrots sleep with one eye open, only closing both eyes when feeling safe enough to enter deep sleep.
Parrots never want to feel vulnerable, so they control how asleep they are. When a parrot sleeps with one eye open, its brain is half asleep and half awake; this is called Unihemispheric slow-wave sleep (USWS).
Its eyes will open if there’s the slightest sound. So, while it may seem like your parrot is sleeping with its eyes open, it’s constantly opening and shutting its eyes as it rests.
If your parrot regularly sleeps with one eye open, don’t take this to mean that it doesn’t trust you.
It may feel safe in your home, but they have certain instincts ingrained into them from centuries of evolution. Even when hand-reared from birth, it’s in a parrot’s DNA to stay alert while sleeping.
Leave your parrot alone while it sleeps. The more time it spends in uninterrupted sleep, the sooner it’ll enter a REM sleep cycle, which is a much deeper level of rest.
A parrot that feels comfortable enough to sleep around you will fully close its eyes. However, a tired parrot on edge will keep its eyes slightly open.
Do Parrots Squint?
Parrots are capable of squinting. However, if you see your parrot squinting regularly, it may be in pain or have an eye infection, such as conjunctivitis or pink eye (a bacterial infection in the conjunctiva).
With a problem relating to the eyes, you’ll usually see some form of swelling or redness. If you don’t see any eye irritation, the discomfort is likely in another part of the body.
Sometimes, a parrot will squint before falling asleep. If your parrot is squinting outside its regular sleeping hours for days, it should be checked by a vet, as squinting signifies physical discomfort.
Parrots have three eyelids: the upper and lower eyelids and the nictitating membrane. The top and bottom eyelids are like our own, fully opening and closing, and the nictating membrane provides further protection from the elements.