common defects of the eye and how they're overcome

• The nervous system enables humans to react to their surroundings and coordinate their behavior
• The nervous system comprises millions of neurons and uses electrical impulses to communicate quickly
• Two common defects of the eyes are myopia (short-sightedness) and hyperopia (long-sightedness)
• Myopia (short-sightedness):

  • Caused by the eyeball being elongated or the lens being too thick and curved
  • Corrected by placing a concave lens in front of the eye
• Hyperopia (long-sightedness):

  • Caused by the eyeball being too short or a loss of elasticity in the lens
  • Corrected by putting a convex lens in front of the eye
• New technologies for correcting vision defects include:

  • Contact lenses that float on the surface of the cornea
  • Laser surgery to reshape the cornea
  • Replacement lens implantation in the eye