Optics External Eye Eye Globe Eye Structures Cornea

Optics

External Eye

Eye Globe

Eye Structures • Cornea – clear window, refracts light • Anterior Chamber – contains aqueous humor that nourishes cornea • Iris – controls amount of light

Eye Structures • Posterior Chamber – contains aqueous humor that nourishes cornea • Lens – refracts light • Vitreous Humor – maintains eyeball shape

Eye Layers • Sclera – protection (clear front is cornea) • Choroid – vascular layer • Retina – nerve layer - Macula Lutea - Fovea - Optic disk

Eye Structures • Retina – changes light energy into chemical energy and then electrical energy • Rods – black/white vision • Cones – color vision: red, blue, green

Flow of Light • Cornea • Anterior Chamber • Pupil • Lens • Vitreous Humor • Retina

Bending Light Terms • Refraction – bending light • Concave – surface with negative curve • Convex – surface with positive curve

Ophthalmic to Optometric • Sphere – add sphere and cylinder • Cylinder – change sign • Axis – Add 90 if 90 or less, subtract 90 if greater than 90

Lensometer • Determine lens prescription • Line up vertical and horizontal lines

Major Disorders • Glaucoma – increased internal pressure due to obstruction in aqueous humor flow • Cataract – cloudy lens • Detached Retina – separation of retina from choroid layer

Major Disorders • Conjunctivitis – inflammation of lining of eyelids • Macular Degeneration – loss of central vision • Strabismus – eyes do not track together

Surgical Interventions • Radial Keratotomy – incisions in cornea to correct myopia • Lasix – reshaping inside of cornea • Scleral Buckle – band to hold retina in place