Biomedical Engineering and the Eye
Dec 18, 2015
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!