Functions of the eye

• Pupil


  Allows light to enter the eye.
• Retina


  Contains cone and rod photoreceptor cells that absorb light rays and turn them into electrical signals
• Optical nerve


  Sends visual information to the brain to be processed.
• Lens


  Can change shape so it focuses light on the retina.
• Cornea


  Bends light so that it travels  through the  lens
• Iris


  The muscle that contracts to change the size of the pupil to control the amount of light
• The lens and cornea refract light onto the retina
• How we see

  • Light reflects off an object, enters the cornea of the eye passes the pupil and is focused by the lens onto the retina
  • The retina contains light-sensitive cells that gather information (light, dark, colour, movement) and send this information to the optic nerve.
  • Light is refracted as it passes through the convex lens, causing the image to flip.
  • The optic nerve transmits the information from the retina to the brain via neurons allowing brain cells in the visual cortex to process the image, turning it the correct way around.