eyes

• What is the sclera


  tough supporting wall of the eye
• what is the cornea

  transparent outer layer that refracts light into eye
• The iris contains muscles that allow it to control pupil diameter
• the pupil controls how much light enters the eye
• what part of the eye focuses light onto the retina

  the lens
• what ligament controls shape of lens

  suspensory ligaments
• where does the optic nerve carry impulses from to the brain

  retina
• what happens when light receptors detect a bright light

  a reflex is triggered that makes the pupil smaller
• what happens to muscles when the pupil shrinks

  ciliary muscles contract radial muscles relax
• what happens to muscles when pupil widens

  ciliary muscles relax radial muscles contract
• what is it called when the eye focuses light on the retina by changing the shape of the lens

  accommodation
• looking at near objects

  ciliary muscles contract suspensory ligaments relax and lens becomes fat (increasing amount of light refracted)
• looking at distant objects

  ciliary muscles relax suspensory ligaments contract and lens becomes thin (decreasing amount of light refracted)
• short-sightedness

  myopia
• long-sightedness

  hyperopia
• hyperopia means objects are brought into focus


  behind the retina
• myopia means objects are brought into focus


  in front of the retina
• hyperopia is corrected with

  convex lenses
• myopia is corrected with

  concave lenses
• name three treatments for vision defects

  contact lenses

  laser eye surgery

  replacement lens surgery
• contact lenses are convenient but have a higher risk of eye infection
• laser eye surgery has a risk of infection and complications
• replacement lens surgery has a higher risk than laser eye surgery and can possibly damage the retina leading to blindness