aphakic lenses
lenses designed for post cataract the crystalline lens removed
Bactericide
a chemical that disinfects and kills pathogenic organism benzalkonium chloride perservative used in lens solution to rid of germs
bullous keratopathy
total swelling of cornea with painful blister formation, treat frequently with therapeutic soft lens
copolymer
2 or more chemicals that combined to form a new chemical compound
endophthalmitis
an inflammation of the entire eye including the outer coats
eversion of the eyelid
folding back of the eyelid on itself
fluid lens
power created by having a very convex or concave lens
hypoxia
low in O2
keratitis
inflammation of the cornea
keratoplasty
a corneal transplant
lenticular lens
relatively large lens most suitable for large, flat eyes, consists of a central optic zone and a surrounding nonoptic flange
nomogram
a table of precalculated math values used to arrive at the specifications of a rigid lens design
pachometer
instrument used to measure the thickness of the cornea and depth of anterior chamber
radial keratotomy
a surgical procedure in which clocklike incisions are made into the cornea to flatten the cornea and correct myopic refractive errors
sopher lens
rigid lens designed with a steep central posterior to accomodate large cones of keratoconus
spectacle blur
blurred vision that lasts more than 30 mins or longer after lens are removed
ulceration of the cornea
a large defect in the cornea which may be caused by hypoxia, trauma, or infection
orthokertology
technique of flattening the cornea and thus correcting refractive errors by the use of a series of progressively flatter contact lenses
0.50D
A PMMA rigid lens weared returns to the office for follow up keratometry. The readings obtained at this time should be within ______ of the original readings
steepen the peripheral curves
what modifications are not possible to perfomr on a RGP lens
loosen the fit
one purpose of grinding the a posterior intermediate curve onto a rigid contact lens would be to
the weight of the lens is reduced
when the diameter of a minus lens is reduced
lens diameter
a change in what affect the lens parameter with the most noticeably effect the lens corneal relationship of a soft lens
flatten the cpc
when performing follow up keratometry one month after the intial fitting, it is observed that the k readings have steepened by a full 2 diopters. What should the fitter do?
silvo
when modifying rgp _____ is not a recommened polishing solutions
Apical alignment GP Fit
-lid attachement, position lens to sit higher -for larger diameter and flat base curve
Interpalpebral Apical Clearance GP Fit
-keep edges thin
lens centered -small diameter and steeper base curve
corneal infiltrate
small white blood cells form as a result to infammatory condition
corneal edema
What can cause a gradual worsening of acuity as the day progresses?
tight lenses
your patients returns to your offic after being fit with soft lenses. She complains of the lenses being uncomfortable and burning as the day progresses. What might be the reason?
damage epithelial cells
which type of cells will be visible with fluorescein stain?
Chalazion
-inflammation of the meibomian -common in male and adults -swelling and no pain -treatment of warm compression
Antimetropia
myopic in 1 eye and hyperopic in the other
Aniseikonia
image in one eye is larger than the other eye
Strabismus
1 or both eye turn up down in out
poor eye movement
7 to 12 times
average blink rate? every 5-8 seconds
Pleomorphism
change the shape of endothelium cells
Polymegathism
change the sizing of endothelium cells
Ptosis
drooping eyelid surgey is required
Ectropion
lower lid everts coming out bandage lens may be used
Entropion
upper or lower lid turns inwards bandage lens may be used
Emmetropia
No vision correction
Ametropia
Refraction is needed
Anisometropia
condition in which two eyes hace unequal refractive power each eye can be myopia, hyperopia, or a combo a difference in power of 2D or more