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| viewing the city skyline at a distance |
I cannot remember the link for this pic, but when you enlarge it, its awesome!
I always am mesmerized by looking at my cats eyes! They are so beautiful really and Sissy's glow green at night like a neon sign, its crazy scary! So here I am googling information about cats eyes.
Unlike human eyes, which work best in day light, the cat’s eyes must
function well in extremely low light condition and as such are well
suited to an animal that is predominantly nocturnal and crepuscular in
activity. Isn't that the truth, you'd think they'd sleep when you do, but they're all up night chasing anything that moves including car lights that might happen to peer in your window. In darkness, cats eyes are able to function in approximately
one-sixth of the light needed for human vision. In low light levels the cats pupil must be able to open as wide as
possible, but also be able to contract to very small size to protect the
sensitive retina in bright sunlight. In human eyes, this size variation
of the pupil is controlled by a circular ciliary muscle, but this
limits the amount of size variation. In cats however, the same process
is controlled by two, shutter-like ciliary muscles, which gives the cat
it’s characteristic slit-like pupil in bright light conditions. All cats
pupils are therefore elliptical, however some, notable the ‘Big Cats’,
appear more circular when dilated.
The size of the cats eye is relatively larger than those found in
human, this enables a larger pupil and therefore more light to enter the
eye. Generally, the lens is more curved enabling sharper focusing even
at the edges of the lens. The size of the anterior chamber and the
curvature of the cornea is also greater, which helps more light to be
refracted onto the light-sensitive retina.
Another feature, which enabled the amount of light hitting the
retina to be increased, is the tapetum lucidum. This is positioned at
the back of the cat's eye, behind the retina and acts like a mirror,
reflecting light back onto the light sensor cells in the retina. This
gives the cats eyes the characteristic night-time glow when they are
caught in a beam of light. Yep, this causes that green scary glow, acting like a mirror. I always wondered if it were harmful to shine a light directly at them but obviously it just hit the mirror and reflects back off right back atcha!
Do cats see in color? I was told that cats saw only black and white, but recent research has shown evidence that suggests that cats may
possess a degree of color vision after all. It’s now believed that cats
can see different shades of the colors blue and green, but that other
colors are not all perceived as we see them. Cats only have two types of cones (photoreceptor cells) in the retina of the
eye that are responsible for color vision. There are three types of
cones, and cats are missing the cones that correspond to the color red.
Humans have all three, allowing us to perceive more color and intensity
of color. It’s believed that cats have a limited ability to distinguish
the difference between reds and greens at all – which is actually a form
of color blindness found in humans as well. So, no, cats do not see the world in strictly black and white form, but they do appear to suffer from a form of color-blindness.
