Mutton and visually impaired pets!

[Matthew_]

Classic bit of human training! I love dogs! You've gotta hand it to them!

[Matthew_]

Sorry, you are going to hate me but here is some more canine trivia along the lines of earlier conversation. This is what Stephen Budianski:

dogs like many other animals, inhabit a perceptual world where things are as likely to be understood and remembered by their smell as by their sight,where mental maps are assembled from avenues and topographies of odour where the unseen is alive and vibrant and the seen is grayer and starker. If we could see through a dog's eyes we would be shocked by what had happened to our most precious link with the world about us: detail lost, blurs that no amount of staring and focusing can alter, a world of wshed out hues and odd shifts of colour. A dog would be equally appalled if he smelled through out nose.

He points out that the most amazing feature of human sight is our power of "accomodation" which is up to 14 dioptres for small children, for a dog it is only 3 dioptres. Many dogs are myopic (up to 3 dioptres of short-sightedness).Additionally, although dogs have a wider field of vision much of it is 2-D and colour vision is very limited. Like keratoconics, dogs struggle with sharpness adn cannot see things like discrete lines easier. On average dogs have 20/75 vision which might sound good to some of us but when add in all the other factors above makes for pretty poor eyesight all round. The biggest issue is that far more of the dog's brain is dedicated to processing smell rather than vision. Primates use an enourmous part of their brains building a visual picture. Dogs do however have the ability to see at night and are very attuned to sudden movement.
There, I have my say about dogs and their eyesight now, I will stop boring you about it!