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