26 Lens

  • cornea sits on top of pupil
  • lens sits behind pupil
  • both work together

  • elongated fiber cells perform anaerobic metabolism

Accommodation

Pathology

Presbyopia

Refractive errors

  • corneal does most of refractions, has to bend lights to set on the retina
  • sometimes while growing, corneal curvature isn't grown right

Myopia

  • negative lens spreads light out

Hyperopia

  • like a magnifying glass

Astigmatism

  • normal cornea circular
  • astigmatism: cornea shaped like football, horizontal focus different from vertical focus

Ectopic Lentis

Cataracts

  • RA taking steroids
  • Also diabetes and galactose deficiency
  • Marfan a risk

Aldose Reductase

  • aldose reductase found in lens of eye
  • diabetes/galactose problem: lots of conversion to sorbitol/galactitol
  • draw in fluid, increase lens osmolarity

Diabetes

Galactose