The Eye

• What type of organ is the eye?

  A sense organ
• What are the receptors in the eye sensitive to?

  Light, intensity, and colour
• Where are all the light-sensitive cells arranged in the eye?

  In the retina
• What is the human eye described as in terms of functionality?

  Complex and effective
• What is the relationship between the eye's structure and function?

  Each structure is closely related to its function
• Which part of the eye refracts 70% of the light?

  The cornea
• What receptor cells are contained within the retina?

  Rods and cones
• What does the iris control?

  The amount of light entering the eye
• What is the pupil?

  Hole which lets light into the eye
• What is the sclera?

  Tough outer coating to protect the eye
• What is the function of the lens?

  Refracts the light onto the retina
• What is the optic nerve?

  Where information from receptor cells collects
• What is the function of the optic nerve?

  Carries nerve impulses to the brain
• What is the fovea?

  Maximum density of cone cells found here
• Where is most of the light from the lens refracted to?

  To the fovea
• What are cones sensitive to?

  Light and colour
• What do rods contribute to?

  Dim light intensity
• What do receptor cells convert light energy into?

  Electrical energy of a nerve impulse
• What happens to the pupil in bright light?

  • Light receptors detect bright light
  • Circular muscles in the iris contract
  • Radial muscles relax
  • The pupil constricts (gets smaller)
• What happens to the pupil in dim light?

  • Light receptors detect dim light
  • Circular muscles in the iris relax
  • Radial muscles contract
  • The pupil dilates (gets bigger)
• What do the ciliary muscles do?

  Change the shape of the lens
• What nerve leaves the eye?

  The optic nerve