Naked Science Forum

Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: Nick Edge on 14/12/2010 18:30:02

Title: What do dogs see?
Post by: Nick Edge on 14/12/2010 18:30:02

Nick Edge  asked the Naked Scientists:
   
I was just wondering if it is true that dogs only see in black and white and how good is their eyesight?

What do you think?

Title: What do dogs see?
Post by: Mazurka on 15/12/2010 14:47:57

As I understand it, Dogs have both Rods and Cones (like Humans) although dogs have a higher proportion of rods (low light) than cones (colour).

Dog cones are only sensitive to 2 colours rather than 3 in Humans.  This effectively means that they are red green colour blind (although I don't think it is quite as simple as that)

Dogs also lack a fovea, which is the sweet spot in the human eye that is 100% cones and has the highest density of receptors, which allows us to see detail. However many dogs have a "visual streak" instead, which is a line with higher density of receptor cells.  It is thought that this helps with tracking rapid movement - an advantage when hunting.

http://www.psychologytoday.com/blog/canine-corner/201009/how-good-is-dog-s-visual-acuity-compared-people
is an article about doggy visual acuity (and how you do an eye test on a dog!)