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Q and A Banner - #3 (World Records-1)

Saturday, October 1, 2011


Dogs have a larger field of vision, but cats can see better up-close.

Cat's eye
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Most people would say cats have better vision than dogs. But loyal dog owners point out, no one’s ever seen a seeing-eye cat!  To find out who has the best vision, let’s look at the world through their eyes:

Dogs can see hand signals from a mile away……But can’t focus on objects closer than 10 inches (which explains why they may miss the two or three pieces of kibble left in their bowl).  While cats are a bit better at seeing things close up

Dogs are champions when it comes to visual field of view. That means when he looks straight ahead he can still see 240 degrees, compared to 200 degrees in cats and 180 degrees in humans.

But both dogs and cats rely more on motion rather than focus, and are rather farsighted, an evolutionary side effect of scanning the distance for prey.

The visual acuity of dogs is about 20/75, although German shepherds, Rottweilers and Schnauzers appear to be even more near sighted. Cats have dogs beat with an average acuity between 20/100 and 20/200 - meaning they can see as much detail at 100-200 feet as humans can at 20 feet!

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Night Vision
We all know that cats have better night vision…… But how good is it? For you to see what a cat sees in the dark, your eyes would have to be 8 inches wide, (18 cm)!   A dog’s night vision isn’t quite as good, but it’s still 3 times better than yours.

The belief that cats can see in the dark is an exaggeration. Felines can see no better in total darkness than humans can, but special night-vision adaptations allow them to see extremely well in even the dimmest light, a vital ability for nocturnal hunters.
To take full advantage of available light, the back of the cat's retina contains a layer of mirror like cells, called the tapetum lucidum, that collects and reflects light back to re-stimulate the retina's rods — much like the effect seen when a car's headlights shine on a road marker at night.

Both cats and dogs have this tapetum lucidum which produces the eerie night-shine that can be seen from their eyes and is why cats require only 1/6th the illumination level and use twice as much available light as people. Dogs’ eyes are about half as efficient as the cats’ but still better at using light than humans.

Colour Vision

But there’s one area where people out-see both dogs and cats: Color vision.  Both cats and dogs have fewer specialize cone cells on the retina able to distinguish colors than people do. But they can see color.  Many people think dogs are colorblind……But they really just have trouble telling the difference between red and green. That’s why they occasionally have to sniff out a red ball you’ve thrown in the grass.

On the other hand, cats probably see more in terms of blue/green shades and appear able to tell the difference between colors that contrast. For cats, pattern and brightness are more important than color. They can see color but it doesn’t matter to them.

And, just like people, an animal’s eyesight weakens with age. Not a lot can be done for cats with eye problems.
But a veterinary ophthalmologist can correct a canine’s vision with contact lenses or special glasses. It may sound a little over the top, but it’s a Godsend to the owners of older service dogs with failing eyesight.


Source(s):  pawnation.com/, tesh.com, globalanimal.org, animaldiscovery.com/cat-guide/

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