Vision
The position of a bunnies eyes affects the way they see the world. Their eyes are near the top of their skulls, which gives them nearly 360-degree vision. But that doesn’t mean they have binocular vision for all of it.
Using two eyes, known as binocular vision, for humans, helps us see the world in three-dimensions. Bunnies, for the most part, rely on using one eye, which is called monocular vision.
Binocular Vision
Binocular vision helps us gauge distances between objects. It also helps us learn how to estimate the height, width and depth of objects. Imagine an object on the table and you go to reach for it, because of binocular vision, you can calculate the scale, distance and position of it.
Monocular Vision
Monocular vision is the opposite to that, where everything becomes flat, like it’s on a piece of paper, and it’s harder to estimate scale, distance and position. For example, if you move towards an object you see it becoming bigger, not the fact that there is a huge gap between you and the object.
Farsighted
They are farsighted which means they see things clearer when they are further away, which can help them see predators coming. The proper name for farsightedness is hyperopic. Bunnies are hyperopic both horizontally and vertically.
Patterns and Shapes
When bunnies are using both eyes (looking forward) they are looking for familiar patterns and shapes. That’s why they will look directly at something to make sense of it. Bunnies have a blind spot in front of their nose and down their spine to their tail. That is why they struggle seeing things directly in front of them. They compensate for that by having a sharp sense of smell, and they use their whiskers and teeth to help them see what’s in their blind spot. Close up, they lose their depth perception. They see in two dimensions, not three dimensions.
Grainy Vision
They also have very grainy vision, and that doesn’t help them distinguish between shapes – this is why it is easy to startle your bunny, they can’t recognise your shape. That’s why it’s good to make familiar noises when approaching your bunny.
Myopic Vision
When you get in front of a bunny, just outside their blind spot, they become shortsighted (myopic). Their vision is about 5-diopters, which means they can see things close up.
Dioptre
Dioptre is a unit that is used to measure a lens’ refractive power. So, bunnies having myopic 5-dioptre means they can magnify items 225% their original size.
Lines of Vision
Bunnies don’t have as good eyesight as us. For example, we can distinguish two lines that are 1/60th of a degree apart (any closer and they blur together). Bunnies can only see lines that are 1/3-1/6 of a degree apart.
What colours can rabbits see?
Let’s simplify a misleading topic
Looky here… This is one of many examples of misleading information on the internet. People have no idea what they are writing, and others believe it, even though it doesn’t make sense.
Let me clear that up.
Rabbits see well in the ultraviolet end of the colour spectrum, ultraviolet, purples, blues, greens into yellow.
They see greeny-yellows better than yellow, but they still can see yellow.
Test it yourself: Show your rabbit a fluro yellow item and see their reaction.
Oranges and reds turn into a blurry grey range of colours with a slight purple tinge.
That is because of their rods and cones. Bunnies eyes have cones and rods like ours do.
Cones provide us with spacial acuity and colour vision, while rods help us see at night.
Bunnies have more 2x rods than we do in their eyes. While we have more cones than bunnies (bunnies have 10x less cones). Having more rods than cones, bunnies can see better than us in low light, but are limited to two-colour vision during the day. That is called dichromatic. That’s why wild bunnies feed at dawn and dusk, they can see better, but everything is nearly in grey scale. They can’t see very well in bright light, or in the dark because of the rods and cones.
Rods and cones are in the back of the eye behind the retina, right near the optic nerve.
Red and Blue Eyes
If your bunny has red or blue eyes, it is an albino. Albinism is caused by a lack or absence of melanin, the protein necessary for pigmentation. Red eyed bunnies are known as ruby (Ruby Eyed White (REW)) and blue eyed bunnies are known as blue (Blue Eyed White (BEW)) albinos. It is caused by a lack of pigment in their iris and choroids, which gives their pupil a ruby-ish reflection within the eye. Albinos will scan their their environment more to gain the same amount of information as a normal brown-eyed bunny who stares.
Ruby-Eyed White (REW) bunnies have no melanin in their system and this shows up as white fur, ruby eyes, clear nails, every part of their body is colourless.
Blue-Eyed White (BEW) bunnies have an incomplete albinism, where they are white all over, have blue eyes, and maybe some coloured markings. The melanin is restricted over the majority of the body. Deafness is common in BEW animals, due to the restriction of melanin needed for hearing.
Melanin
Melanin helps develop parts of the eye, including the iris, retina, eye muscles and optic nerves. The absence of melanin results in the eye not being developed properly snd the bunny will have problems focusing, depth perception and tracking.
Scanning
Scanning is when the bunny moves their heads from side to side to help judge distance, or they have exaggerated eye movement. Eye movement is called nystagmus which is the microscopic movement of the eye that changes focus or the depth perception.
It may seem scary seeing a rabbit do it, because they sway slowly back and forth in order to see an object, which can look like they are breathing heavily, or look like it is stressed.
Ruby eyed rabbits scan more than blue eyed rabbits. Usually, the rabbit does it from birth, but if there is a change in the behaviour suddenly, it may mean a vet trip is in order as it may indicate further health problems.
Bunny Eye Colours
These are some of the variations of bunny eye colours.
The Colours Bunnies See
They see within the colour spectrum range of 360nm and 580nm. In human terms they would be classed as colour-blind, but in actual fact, they aren’t. They can see better than us in certain situations.
Wavelengths between 100nm – 390nm are part of the UV range.
- UVA (315-400nm)
- UVB (280-315nm)
- UVC (100-280nm)
That means bunnies can see in the UVA range, as well as purples, blues, greens and greeny-yellows. Bunnies can see up to 580nm, which is only really missing out on the yellowy, oranges and red colours.
Humans can see from 400nm to 700nm. We can’t see ultraviolet and infrared, they are invisible to us, but we can feel their heat on our skin. After all, they are a form of radiation.
Bunnies cannot see infrared, it is invisible to them, but like us, they can feel it through heat.
The full light spectrum including ultra violet and infrared is 100nm-1mm. Keep in mind, that the measurements are the lengths of the waves. The longer the waves, the slower they move.
Bunnies are 8x more sensitive to daylight than we are. Their eyes can take up to 30 minutes to fully adjust to daylight when coming from a dark or dull place into direct sunlight.
When a bunny is outside, their vision in sunlight or shade is quite grainy. While at dawn or dusk, their vision is much clearer, because they are only concentrating on ultraviolet and grey scale colours.
Ultraviolet light vision
Most animals have some sort of UV vision
Before 1990, only a few animals were recognised as being able to see in the ultraviolet wavelength, now, we know that many animals can detect and respond to it. It is used for choosing a mate, communication and foraging for food.
Having the ability to see UV light waves means that rabbits don’t see colours the same as we do. They would see heat signatures and particle effects around animals and food, as well as vivid blues, purples and greens that glow.
A hawk, 1km up in the sky, can see a mouse on the ground rummaging around. They see the mouse through ultraviolet vision, where the hot bits glow brighter than the cooler bits.
With the UV part of the spectrum, parts of birds beaks glow white, budgies glow pink and vibrant blue, flowers have dark middles and the petals are white or a light purple, and pollen glows like little golden dots.
These balls show the difference between how we see colours compared to the colours rabbits are suspected to see.
The reason why oranges and reds turn purpley-grey for a rabbit, is for the same reason why we can’t really see purple. Humans can’t see purple because there is no wavelength that makes it appear as a colour. What we see is our brain mashing red and blue together to make something it thinks best represents the colour in between, we call it purple. Purple is a non-spectral colour, it doesn’t have a wavelength. Rabbits, dogs, cats, animals in general, aren’t really seeing purple either, like us, it is a non-spectral colour. Because rabbits can’t see oranges and reds, to a rabbit they are also non-spectral colours, they are mashed together and turn a purpley-grey colour.
Anecdotal example of bunny vision
During the day, bunnies see everything as grainy/pixellated blue and green. When it comes to dawn or dusk, their vision changes to grey scale and quite sharp.
Imagine you’re a wild rabbit, at dusk, in a paddock of grass. You are busy eating grass shoots. Everything is grey scale. You hear a rattle in the bushes and your eye turns to look at it. It’s another animal. You can see it through your UV vision, sensing the heat and movement in the forest. Vision out of your single eye is 2D, so you can’t judge distance.
It rattles again, you turn your head so both eyes look at the animal. Your vision turns to 3D, and you can calculate the distance between you and the glowing animal. It is about 1km away in the forest line. It’s a fox. You listen out for its movement, to check whether it has seen you. It hasn’t… yet.
You make ultrasonic noises to tell your colony to move backwards slowly to not draw attention.
You’re safe.