1. Independent evolution across species – Convergent evolution has produced a very similar eye across species; mammals and cephalopods’ common ancestor had a photoreceptive spot.
  2. 8% of males can’t see green – Or red! X chromosomeinherited mutations can lead to colour blindness, the most common of which is red/ green colour blindness.
  3. Hawks have 20/2 vision! – Hawks have up to eight times better vision than the average human due to increased levels of cones and rods in the eye.
  4. Your eyes don’t get tired – The eye is the only organ of the body which doesn’t actually need rest. It can operate at 100 per cent all the time.
  5. Over half the brain is involved in seeing – The eye uses 65 per cent of the nerve pathways to the human brain. We are very much visually dependent beings!