Why Do Cats’ Eyes Glow in the Dark?

A cat’s unusually large eyes are perhaps their most striking features, and never more so than at night. When they seem to glow in the dark with an almost supernatural light.  The cat is a nocturnal prowler, and heir powerful sense of vision is what makes them so successful.  But how exactly do the eyes work? Well, not quite.  Heres’ how it works.

The feline eye structure includes the cornea, which is the clear, curved part of the eyeball in front of the pupil, the iris, which gives the eye its color, the lens, located behind the iris, the retina, consisting of a network of light-sensitive cells, and the tapetum lucidum, a Latin term that translates as “bright carpet.”  The cornea, lens.  The leans bends the light rays, focusing them to form an image on the retina.

Where does the tapturm lucidum come in?  It is what allow the cat to take in extra light in dim situations.  Lining most of the back of the retina, the tapetum lucidum acts as a mirror, reflecting light that was not absorbed the first time it passed through the retina.  The result is the glow, called eye shine, that you see when light strikes your cat’s eyes in a darkened room.  A cat can see no better than you or I when in a situation of total darkness, but when some light is present, the tapetum lucidum allows the cat to make better use of it.

Why do some cats’ eyes glow red while others glow green?  Certainly not because of any demonic influence.  The color of the light reflected back from the tapetum lucidum is related to the color of the cat’s eyes.  Cats with green or yellow eyes tend to reflect grenish light.  Cat with blue eyes, such as Siamese, tend to reflect reddish light.  Now you know!

 

 

default