Have you ever looked into the eyes of a rabbit and wondered what exactly they can see? While floppy and cute, rabbit eyes are complex organs optimized for survival in the wild. Through their expansive sideways gaze, rabbits remain vigilant for threats across nearly 360 degrees. Their eyes never fully close while sleeping and can penetrate the darkness of night with eerie clarity. But limitations exist too. Blind spots leave rabbits unable to see what lurks right under their nose. Join us on an optical adventure to discover 7 awesome facts about how rabbits view the world, along with 5 common problems that afflict their vision. You’ll gain new appreciation for the visual powers of these hopping creatures after learning what makes their eyes unique.
7 Awesome facts about rabbit eyes
Rabbits have unique and interesting eyes that allow them to see the world in a different way than humans do. Here are 7 awesome facts about rabbit eyes:
1. Rabbits can see behind them
Rabbits have eyes located on the sides of their heads, giving them a panoramic field of vision of about 340 degrees. This allows them to see almost completely around their body without turning their head. Having nearly 360 degree vision is extremely beneficial for prey animals like rabbits so they can spot predators sneaking up from behind or from the sides.
2. Rabbits sleep with their eyes open
Rabbits don't have eyelids like humans that close when they sleep. Instead, their eyes remain open when they sleep. To protect their eyes, rabbits have a third eyelid called a nictitating membrane that acts like built-in goggles. The nictitating membrane comes up from the bottom of the eye to cover and lubricate the eye while rabbits sleep.
3. Rabbits only blink once every 5 minutes
Rabbits blink far less frequently than humans, only closing their eyes once every 5 minutes on average. Since rabbits are prey animals, minimizing eye closure reduces periods of blindness and allows them to continuously scan for threats in their surroundings.
4. Rabbits can’t see red
The retinas in rabbit eyes lack red light receptive cone cells. This means they can only see blue and green light, and their worldview lacks the color red. As a result, red objects simply appear as dark or gray to a rabbit. Rabbits can still differentiate blue from green, so they don't see the world in simply black and white.
5. Rabbits have grainy night vision
Rabbits see well in dim light due to a reflective surface behind their retina that amplifies light. However, this comes at the cost of visual acuity. Rabbit night vision has low resolution and is very grainy compared to human vision. Still, being able to see at night helped ancestral wild rabbits avoid nocturnal predators.
6. Rabbits are farsighted
Since rabbit eyes are positioned on the sides of their heads, they have good peripheral but poor frontal vision. Rabbits also cannot focus on objects closer than about 50 centimeters in front of them. So while they can detect faraway movement, rabbits have difficulty seeing details of objects up close.
7. Rabbits have trouble seeing objects in 3D
Rabbits lack stereoscopic vision, or the ability to perceive depth and see in 3D. Since their eyes are located on opposite sides of the head, they don't get overlapping fields of view. Rabbits instead rely on monocular depth cues like motion parallax and perspective to judge depth and distance. This makes it harder for rabbits to detect camouflaged objects.
Bonus Fun Facts
Why do rabbits' noses wiggle?
A rabbit's constantly twitching nose is key to its sense of smell, which is just as important as its vision. The muscles in the nose actively move scent molecules over the olfactory receptors to help the brain locate smells. The nose moves back and forth to provide stereo smelling and pinpoint odor sources.
Why are rabbits' ears so big?
Rabbits have prominent, elongated ears that allow them to detect faint sounds from far away. Their large ears are packed with blood vessels to aid thermoregulation. Rabbits also have impressive directional hearing and can rotate their ears independently to pinpoint sound sources. The ear position and posture provides insight into a rabbit's mood and mindset as well.
5 Health problems with rabbit eyes
While rabbit eyes are evolved for life as prey, they are still prone to certain health issues. Here are 5 common eye problems in rabbits:
1. Cataracts
Cataracts in rabbits involves progressive opacity of the lens, causing visual impairment and eventual blindness if untreated. Cataracts tend to develop from old age, diabetes, eye trauma, inflammation, and sometimes genetics. Surgery to remove cataracts may be an option for rabbits.
2. Weepy eyes
Epiphora, or weepy eyes, occurs when tear production exceeds the drainage capacity of tear ducts. The excess fluid spills out, wetting the fur around rabbits' eyes. Causes include dental problems, conjunctivitis, blocked tear ducts, and other eye infections.
3. Red eye
Red eye or bloodshot eyes develop from dilation of the conjunctival blood vessels. This can result from ocular injuries, infections like conjunctivitis, foreign objects scratching the eye, or eye strain from bright light. Certain diseases like glaucoma can also cause red eyes in rabbits.
4. Crusty eye boogers
Eye boogers refer to the crusty mucus discharge that can accumulate in the corner of rabbits' eyes while sleeping. Some wetness is normal but excessive buildup or yellow/green color can indicate infection. Thorough eye cleaning and antibiotic drops/ointment can treat minor cases.
5. Abscesses
Abscesses are pockets of pus that form under the skin when bacteria invade tissues. Abscesses near the eye, tear ducts, and conjunctiva are common in rabbits. They appear as swollen bumps around the eyes and require antibiotic treatment. Otherwise, eye abscesses can rupture, spread infection, and damage vision.
Monitoring rabbits' eyes for any abnormalities, redness, swelling, discharge, or vision changes allows early detection and treatment of eye problems before they become severe. With prompt veterinary attention, most rabbit eye issues can be managed for a good quality of life. Proper diet, sanitation, and annual checkups help prevent eye disease in rabbits as well.