georgeUntil a few years ago, everyone thought that dogs' eyes...

george

Until a few years ago, everyone thought that dogs' eyes all had the same basic structure and Dog A saw things the same way that Dog B did.

However, an Australian professor of veterinary science named Paul McGreevey started wondering about this and hooked up with a neuroscientist named Alison Harman, and they started studying the eyes of different kinds of dogs. Different kinds of dead dogs.

Dogs have something called a visual streak. It's a line of vision cells packed in there very densely and running across the retina. Scientists already knew this.

What McGreevey and Harman found out, however, was that some dogs don't have the visual streak. Nobody knew that before. Instead some dogs have something called an area centralis, which is a whole bunch of vision cells arranged in one spot, as opposed to stretched out in a streak.

Dogs with an area centralis probably see things more like we do than dogs equipped with visual streaks.

Visual-streak dogs tend to be hunters. They have long noses and good peripheral vision and can spot something moving out of the corners of their eyes and follow it with their eyes.

Area-centralis dogs tend to have shorter noses, and they have about three times as many nerve endings in the retina as do visual-streak dogs. That means they may not have great peripheral vision but they see things much more clearly, with greater definition, than other dogs.

Now I don't know if this has been absolutely proven, but the thinking is that maybe short-nosed, area-centralis dogs are more likely to watch TV than long-nosed, visual-streak dogs.

In the interview I read, McGreevey said this also might explain why short-nosed dogs can seem to be more attentive than long-nosed dogs. They are able to read your facial expressions better because of their ability to see up close. That's an interesting idea.


regards

ps - that ain't my work :)