Correcting vision defects

• Long-sightedness (hyperopia)

  • Unable to focus on near objects
  • Occurs when the lens is the wrong shape and doesn't refract the light enough or the eyeball is too short
  • Images of near object are brough into focus behind the retina
• Long-sightedness (hyperopia)

  • Can use glasses with a convex lens (lens which curves outwards) to correct hyperopia
  • Lens refracts light rays so they focus on the retina
• Short-sightedness (myopia)

  • Unable to focus on distant objects
  • Occurs when the lens is the wrong shape and refracts the light too much or the eyeball is too long
  • Images of distant objects are brought into focus in front of the retina
• Short-sightedness (myopia)

  • Can use glasses with a concave lens (lens which curves inwards) to correct myopia, so that the light rays focus on the retina