Biomedical Engineering and the Eye

Eye Anatomy

3 major categories of eyesight problems 1._____________ 2.Nearsightedness (___________) 3.Farsightedness (___________) Astigmatism Myopia Hyperopia

Astigmatism ___________is not evenly round Light focuses at _________________ _________________ inside the eye Some parts of what you look at are in focus, other parts are blurry Fix by _____________cornea

Nearsightedness Unable to see __________ things clearly Eyeball is ___________ Light focuses in front of the retina Glasses or flattening the cornea fixes it

Farsightedness Unable to see ___________things clearly Eyeball is too _________ Cornea is too _________ Light focuses behind retina Glasses or making the cornea rounder fixes this

LASIK surgery Vision correction procedure Uses two different biomedical devices – _________________ – ____________ laser Reshapes the ______ Changes the way light is refracted (bent) into the eyeball Light will then focus on retina…CLEAR VISION!

Microkeratome Very precise, mechanical shaver – Like a razor for your eye __________________is guided over the eye on a ___________________ Cuts a thin, outer layer of the ____________away from the eye Tracks have a ring – Ring uses suction to hold eye still Video on microkeratome

Excimer Laser “_________” laser – Does not heat up Removes ____________tissue by exposing it to UV light Very precise tool

Continuous Medical Implants Treat: ___________ – Inflammation of the inside of the eye ___________________ ___________________ (DME) Age-related macular degeneration (AMD)

Retisert ________________________ ________________________ – About the size of one grain of rice! Surgically implanted in the eye – 1 hour outpatient procedure Releases medicine ________________________ ________________________ – Controls inflammation Intraocular pressure and cataracts can develop

I-vation __________________________________ Helical metal screw Medication slowly released into eye

Artificial Retinas Treat: ___________________ – Genetic – Breakdown of ____________________ – Loss of night vision, then peripheral vision, then all vision

Artificial Retinas Implanted in the ____________________ Stimulates __________ for blind patients – Can see blurry shapes 2-mm wide chip Light powers 5,000 ____________________ Causes ______________ signal to _____________ cells in the back of the eye __________pass signal on to the ____________

Design!