high minus / high plus Flashcards
does a high myope or high hyperope have a higher risk of retinal detachment, glaucoma and cataract>
high hyperope
myopia management
-wear rigid contacts at night . OrthoK
-wear myopia controlling contacts (MiSight)
-pharmaceuticals (ATROPINE)
-myopia management eyeglass lenses
Myopia glasses lenses
-Miyosmart by Hoya (62% proven to slow myopia in children)
-Myokids lenses by zeiss (20% proven to slow progression)
things to consider when choosing the right lens
-power of rx
-eye size
-frame PD / px PD decentration
-px tolerance to thickness
-budget
index of refractions
1.5
1.53
1.59 (poly)
1.6
1.67
1.74
1.8 / 1.9
when having a high minus rx is it better to use a bigger or smaller frame
smaller that way when edging we can edge off all of the thickness on the edges
myodisc
commonly used back in the day to correct high minus and high plus
-centre of lens will be the pxs try power and the outside will be a smaller power / this allows for the frame to be lighter
-since there are different powers it will create fishbowl effect
3 main causes of aphakia
the absence of the lens in the eye.
1. cataracts
2. injury
3. congenital defect
with aphakia you will ..
-have more glare and more scattering
-reduced field of vision
-struggle with differentiation colours
-
high plus power frame choice
we want a larger B size
-less wrap and less panto
-round corners
-NEVER USE DRILL OR NYLON
do plus lens gain or lose powers when you move it away?
gains power (increasing vertex and effective power)
do minus lens lose or gain power when you move it away?
loses powe (increasing vertex, decreasing effective pwoer)
what frame to chose for minus lenses
-smaller frame (nothing to wide because we want to cut off thickness)
-circular / round shape which allows us to cut all thickness off
-AVOID SHARP EDGES
-plastic frame to cover edge thickness
