Rods and Cones

• Rods provide low detail, black & white images, good for seeing in low intensity light (at night).
• Cones provide detailed, coloured images; they work in high light intensity.
• Rods are packed most tightly around edge of retina so you can see things most clearly when not looking directly at them.
• Cones are most tightly packed at centre of retina, so objects are seen most clearly when being directly looked at.
• Fovea:

  • Part of the retina where the receptor cells are pushed most closley together
  • Where light is focused when you look straight at an object