senses

• • protects inferior structures
  • white part of the eye

  sclera
• • Allow light to enter
  • transparent

  cornea
• • circular opening in the center
  • decrease and increase the amount of entering light.


  pupil
• • colored part of the eye
  • regulates the amount of the light

  iris
• • produce clear vision
  • focuses images onto the retina

  lens
• • 120 millions rods (dim light)
  • 6 million cones
  • Inner layer

  retina
• • eye to the brain
  • special sensory nerve
  • translate light into nervous signals

  optic nerve
• eye motion and movement

  extraocular muscles
• • watery solution
  • produce the drain tears into the eye

  lacrimal apparatus
• protecting the eye


  eyelids
• oily secretion that lubricates the eyes

  meibomian glands
• sweat glands between the eyelashes

  ciliary glands
• • reduce eye infection
  • dilute salt solution

  lacrimal glands
• detect light waves

  photoreceptors
• low intensity light (for night vision)

  black and white

  rods
• high intensity light

  for day vision

  cones
• • long range or short range focus
  • change the shape of the lens
  • aranged in a circles

  ciliary processes