The eye

• What does the cornea do + what is it

  • Refracts light into the eye
  • Transparent outer layer at the front of the eye
• What does the iris do

  Controls how much light enters the pupil
• What is the pupil

  Hole in the middle of the eye
• What does the lens do

  Refracts light + focuses light onto retina
• What does the retina do

  • Contains receptor cells which are sensitive to light intensity + colour
• What are the 2 receptors cells apart of the retina

  • Rods -> sensitive to light intensity + but don't detect colour
  • Cones -> sensitive to different colours of light + but not good in dim light
• What does the optic nerve do

  Carries impulses from receptors on the retina to brain
• Label the eye

  Iris, cornea, pupil, lens, retina, optic nerve

  
• EYE LABELLED

  
• What happens if there is bright light

  Iris changes shape -> pupil becomes smaller -> less light enters eye
• What happens if there's dim light

  Iris changes shape -> pupil becomes bigger -> more light enters eye