B10.5 The Eye (Close and Far Objects)

• What must the lens be to refract light from a close object?

  Short and Fat
• What do the muscles in the eye do when an Object is close?

  • Ciliary Muscles contract inwards towards the lens
  • Suspensory ligaments slacken so the lens can return to its regular fat shape
  • This is so it can refract light more strongly, so it hits the Fovea
• What do the muscles in the eye do when an Object is far away?

  • Ciliary muscles relax outwards from the lens
  • Suspensory Ligaments pull the lens taut to weaken the strength light is refracted at
• What is the Scientific name for Long-Sightedness?

  Hyperopia
• What does it mean if you have Long-Sightedness?

  • Your eye can't refract light enough, causing images to be focused behind the retina
  • This means close object appear blurry
• How can Long-Sightedness be fixed?

  • Spectacles with a Convex lens refracts the light more so it focuses better on the Fovea
• What is the scientific name for Short-Sightedness?

  Myopia
• What does it mean if you have Short-Sightedness?

  • Your eye over refracts light rays, causing the image to be focused before the retina
  • This makes far objects blurry
• How can Short-Sightedness be fixed?

  • Spectacles with Concave lenses, to counteract the refracting the eye would be doing