which parts of the eye see colour which parts of them see black and white??

Question: which parts of the eye see colour which parts of them see black and white??
- Keywords:
  black,
  colour,
  cone,
  eye,
  part,
  retine,
  rod,
  vision,
  white
Asked by helenstride to Steve on 22 Mar 2011.
- Stephen Moss answered on 22 Mar 2011:
  
  Hi Helen
  Great question. We have two types of light-sensitive cells (photoreceptors) in our eyes, the rods and cones. The cones come in different colours (red, green and blue) and unsurprisingly are used for colour vision, and we use those during normal daylight (or artifical light). The rods are actually ‘switched off’ during the day, and only become activated when light levels get very low – so late in the evening and at night.
  
  Rods can’t detect colour, which is why at night everything looks varying shades of grey, even things that we ‘know’ are coloured. Interestingly, we have about 4 times as many rods as cones, and most of our cones are crammed into a single spot at the back of the eye.

Question: which parts of the eye see colour which parts of them see black and white??