Your cornea is the clear front part of your eye. It is like a window that controls and focuses the light coming into the eye. If your cornea has an irregular shape, the light does not focus properly. Everything looks blurry. This is a refractive error.

Four common refractive errors are:

  • Myopia, or nearsightedness – clear vision close up but blurry in the distance
  • Hyperopia, or farsightedness – clear vision in the distance but blurry close up
  • Presbyopia – inability to focus close up as a result of aging
  • Astigmatism – focus problems caused by the cornea
  • Glasses or contact lenses can usually correct this problem