Does My Dog Need Glasses??
I have a dog, his name is Khan. He’s a 9 month old Labrador and Golden Retriever mix, so a pretty smart dog! He’s very active bordering on hyperactive and needs lots of attention and play time. We go to the park and play ball, which usually involves me throwing the ball and Khan, being the smart one that he is brings it back to me. He’s very good at this for the first couple of times, but then he just stops. I throw it, he runs after it, and then when he gets to it, he just doesn’t seem to see it even though it’s right there.
For instance, I threw it into the bushes once, he bolted on over there, rummaged around for a minute or two, trampled through the undergrowth, head swinging from side to side, tail wagging in complete earnest… and completely missed the ball! He just did not see it when it was obviously right under his nose.
On the flip side of that, my daughter was walking towards us across the park, quite far away. I could barely see her. But Khan looks up, and zooms off in her direction. So he can obviously see far away, but perhaps not up close.
Given that I have been working at Eyesey Eyecare, the opticians for a year now, I’m totally immersed in the world of good and bad eyesight. So this got me thinking. Is this issue that I have experienced with Khan a visual problem? Or is it that he just loses interest in the game?
My initial thought, was, perhaps he needs reading glasses. Humans do, so why not dogs?? But then I thought hang on a second, might there be a different explanation for this?
I started looking at colour vision. Humans have 2 types of light sensitive cells within the eye; rods and cones. The cones are sensitive to colour and are responsible for colour vision. Humans have 3 types of cones; red, green and blue. Dogs however only have 2 cones; blue and yellow. This is very similar to humans who are colour blind/colour deficient, meaning that dogs cannot distinguish between greens and reds.
The ball I use is green. So my theory is that he cannot distinguish the green of the ball from the green of the undergrowth. Perhaps I should be using a blue or pink ball – something that provides better contrast for Khan.
Watch this space to find out whether my theory is correct.
by Milica Macdonald
Tags: blog, colour vision, dog eye test, reading glasses