Eyes

From WabbitWiki

What is a rabbit's field of vision?

The rabbit cornea is large and occupies 30% of the globe, and their eyes are directed more laterally than most mammals. These two features give rabbits a panoramic field of vision to detect predators easily.[1]

However, their eyes cannot visualize the small area beneath the mouth, and rabbits depend on their lips and whiskers for food discrimination in this blind spot.[1]

An infograph from Tamsin Stone. How do rabbits see the world?

Do rabbits see color?

Rabbits are not color-blind but their color perception is limited. The retinas of mammals contain two kinds of light-sensitive cells -- cones and rods. Cones detect bright light and contain pigments that give the ability to see color while rods are activated under low light and lack the color-vision pigments.[2]

The retinas of the domestic European rabbit have been studied to hold many more rods than cones -- rods in the domestic rabbit retina reach a peak density of about 300,000 per square millimeter in contrast with cones which reach a peak density of about 18,000 per square millimeter. These cones are sensitive to either green or blue light but not to red, so rabbits are limited to dichromatic (two-color) vision. Most of the retina is dominated by green-sensitive cones, but there is a small area with no green cones and many blue cones. It is unknown what this means for a rabbit's color vision, but rabbits do not seem to pay much attention to color.[2] Note: The study that this information comes from used the New Zealand breed of rabbits. 2–3 kg and 2–3 months old.

Do rabbits blink?

Rabbits blink approximately 10 to 12 times an hour.[3] They also possess a third eyelid (nictating membrane) that does not actively blink (nictate) but passively covers the cornea when the globe is retracted in its socket. The third eyelid does not move more than two-thirds of the way past the cornea and partially closes with sleep or under anesthesia.[3][4]

Why is my rabbit swaying their head side to side?

Rabbits may sway their heads to for depth perception normally (scanning), or it can be a sign of disease such as an ear infection or E. cuniculi. Swaying as a result of disease usually results in a tilted head (head tilt), while normal scanning, especially in ruby-eyed white rabbits (REW), will have a more upright and straight head position. Normal rabbits may sway their heads back and forth to take advantage of parallax for depth perception.

fusionramjet. (2006). Stevie scanning. This is a normal healthy rabbit scanning for depth perception in a REW rabbit.
Jennie Masanz. (2012). Scanning. This is normal healthy rabbit scanning in a Holland Lop.
RSPCA Guildford & District Branch: REW bunny 'scanning'. This is normal healthy rabbit scanning in a pointed white lionhead rabbit.
Wheek Wheek Thump. (2013). Bunny Head Sway. This is head-scanning by a rabbit that was diagnosed with E. cuniculi.

What are some common eye problems in rabbits?

Below are some resources about rabbit problems with eyes.

What is an enucleation?

Enucleation is the surgical procedure that removes an entire eye globe and connecting tissues, leaving behind the lining of the eyelids and muscles of the eye.

Experiences

Further reading

See also

References

  1. 1.0 1.1 Quesenberry, K & Carpenter, J. (2012). Ferrets, Rabbits, and Rodents: Clinical Medicine and Surgery. (3rd ed.).
  2. 2.0 2.1 Lumpkin, S & Seidensticker, J. (2011). Rabbits: The Animal Answer Guide.
  3. 3.0 3.1 Varga, M. (2013). Textbook of Rabbit Medicine. (2nd ed.).
  4. Mitchell, M.A & Tully, T.N. (2009). Manual of Exotic Pet Practice.