Question: How can scientist say dogs can only see in black and white what evidence proves this?????

Daniel Hewson answered on 15 Jun 2015:

That’s an interesting question. To start with we need to understand how we see colour because the light that enters our eyes is not colourful, it is simply a packet of energy in the form of a wave. We see colour because our brain interprets the wave lengths of light. To help the brain we have cells in our eyes that receive and respond to the light. We have two types of cell called rods and cones. Scientists have discovered that our cone cells produce colour vision and our rod cells are effective when light is dim. We have three cones that detect red green and blue light. Dogs only have two cone cells which means they can detect blue and yellow but not red and green – this we call colour blindness. Scientists have found that dogs can see in colour but not the full range of colour that we can see.