Scientists say that birds have the most powerful eyesight among animals, humans, and birds.
Since the evolution of the birds, their strong eyesight has helped them a lot to evolve and make it through the physical world, which is full of dangers for them.
Some birds can spot their prey from miles away.
But what empowers birds with such a powerful vision? The answer is their large eyes.
Large eyes mean their vision is expanded, and they can see a lot more than what humans can. These large eyes help them navigate fast through the thick and dense forests and hide from a hunter bird or catch a smaller one.
Also, the eyesight depends on whether they are diurnal birds or nocturnal birds. Nocturnal birds such as owls are among the birds with the largest eyes.
Hawk and other hunter birds also have larger eyes to catch a bird.
Understanding Birds Eyes
The structure and the receptive cells differ between a human eye and a bird’s eye. Eyes have photoreceptor cells that take in the data from the eyes and send it to the brain to process it. There are two types of these cells.
Rod cells are light-sensitive cells that enhance vision in low-light conditions.
Cone cells are color-sensitive cells. They perceive colors and spectrum and help during the day.
Nocturnal animals such as owls have more rod cells in their eyes, while diurnal birds have more cone cells.
The fovea is another part of the eye that’s worth a discussion. The photoreceptor cells are dense here; thus, the picture is also the sharpest.
In predatory birds like falcons, there are two foveas that allow them to see so clearly up to a great distance.
But what helps the birds see to such great distance and navigate so easily and quickly through the woods is their brain.
A large area of their brain is focused on visual processing. They perceive actions and movements faster and act accordingly.
How Far Can A Bird See?
Birds have better eyes than humans, but, hawks beat humans by the most margin among all birds. They can see into a distance eight times farther than humans.
If compared to better vision, owls are far ahead of humans. Their eyes face forward, but their head can turn sideways. In fact, owls can rotate their neck, having a 270-degree vision range. Their eyes work far better at night than they do during the day.
The story of flying birds is different. They have more receptors than humans, and thus they can see kilometers ahead while flying. Even during the flight, their vision is several times better than humans.
How Do Bird Eyes Differ From Human Eyes?
First, humans have smaller eyes than birds. They have larger eyes to cover a larger area. When compared to its body, a bird’s eyes proportion is far more than a human’s.
Also, birds see far more colors than a human. The reason resides in their retina, which has four cones compared to human’s three. They can also perceive the ultraviolet spectrum, which is not visible to human eyes.
Because of the advantage of added spectrum-watching capability, they can spot things far better than a human.
They can see the same colors as humans but perceive the UV spectrum first; thus, they can spot fruits easily. They can also see past a bird’s plumage to ascertain its gender which humans can’t.
For humans, it is difficult to tell a male from a female, but not for birds. This vision also allows them to locate their prey, chasing their trails.
Why Do Birds Have Eyes On Either Sides Of Their Heads?
Some birds, such as parrots and pigeons, have eyes on either side of their heads. The reason? Because they are the prey birds.
Prey birds who need protection from predators have eyes on the sides of their heads. Their eyes move independently of each other.
The left eye covers the entire left region, while the right eye covers the right region. It is called monocular vision. It allows them to see both sides.
Unlike these birds, humans have binocular vision. They have both eyes forward. Their vision is smaller, so they focus entirely on the objects ahead. Also, human eyes work together.
Predator birds like hawks, owls, falcons, etc., share this human trait. They have their eyes in front, which allows them to focus on their prey. The depth perception of these predators is great.
Can Birds Move Their Eyes?
No. It is something where humans beat birds. Humans have little eyes which can roll in their eye sockets. But bird eyes are large, and their heads are small; thus, there is little room for movement.
Birds, therefore, move their heads instead of their eyes.
Can Birds See Through Windows?
Birds don’t see glass, and thus, you have to help them sometimes when they hit your window glass and fall.
If your windows are closed, and the sun is shining, there is little possibility that they will see you. Their eyes detect movements, and if the room is lightened without glass reflecting light, and you move about, they will see you; they don’t care about the glass between you and them.
Which Birds Have The Best Eyesight?
Some birds hold the crown for the best eyesight in the world. These are falcons and hawks. Be it underwater, on land, or a flying bird, these birds don’t miss their prey.
They can see eight times farther than humans, and even while flying, they can see up to three kilometers of distance. .
Their amazing speed helps their binocular vision, and after spotting a dot-like mouse from high above the sky, they race towards it with their majestic speed and catch it.
Owls are also the ones who prey at night, thanks to the rod cells behind their eyes. Their eyes are fixed, and they rotate their head.
These nocturnal birds also hold the crown for the largest eyes in proportion to their body weight.
When talking about eye size, an ostrich has the biggest eyes in the entire bird kingdom and any land vertebrate. However, they are far behind many birds in proportion to their body.
Which Birds Have The Poorest Eyesight?
Kiwis have the poorest eyesight. They are nocturnal birds that prey at night. They don’t use their eyes much but depend on other senses such as hearing, smell, and touch.
They have very small eyes. In fact, they are called blind kiwis now, as they are on the verge of losing their eyesight.
Different Bird Eye Positions
Ducks have eyes high on their heads to see forward as well as keep an eye behind them. They can also see upward, but their forward vision isn’t very good.
Birds with eyes on the sides of their heads are prey birds, while those with forward-facing eyes are predators.
American Woodcock is known to have a 360-degree vision as it can see everywhere around it as well as above it.
Some birds also sleep with one eye open. They give rest to one part of their brain, and with an open eye, look out for predators.
Birds are very different creatures. They are colorful, intelligent, and farsighted.
The differently-located eyes help the birds protect themselves and survive in this world. Birds have evolved as per their needs and what you see today is the result of centuries of evolution.
This guide has everything you need to learn about bird’s eyes. Hoping you will have found some amazing facts about birds here that were unknown to you before.