-2.00D OU with a PD of 63.
The were made with PD of 66. How much total prism and in
what direction? Correct Answer 0.6 BI
OD: -2.00 X 1.5 /10=0.3
OS: -2.00 X 1.5 /10=0.3
Total: 0.6 BI because OC's wider than PD
"Conventional" slab-off is ground with base up prism in the
reading portion only on the lens with the ________ in the
verticle meridian. Correct Answer most minus power
+2.75 -1.00 x 180
The refractive anomaly indicated by this Rx is Correct Answer
simple hyperopic astigmatism
A +1.75D lens fabricated with a +6.00 BC will require a back
curve of? Correct Answer -4.25
Why? +6.00-4.25=1.75
a +10 lens is fit at a 14mm vertex distance. A new frame is
chosen which positions the back surface 9mm from the cornea.
The power of the lens needed to compensate for the change is:
Correct Answer +10.50
General rule of thumb: a +10.00 lens moved a distance of 5mm
will change by approx. 0.50D
A cataract may be in: Correct Answer nucleus of the lens
capsule of the lens
and cortex of the lens
,A condition in which the refractive error of one eye differs from
that of the other (both eyes have the same sign) Correct Answer
anisometropia
A diverging lens produces _______ image Correct Answer
virtual
a farsighted eye is one that is __________? Correct Answer
hyperopic
a frame contains 8 degrees of pantoscopic angle ideally, the gaze
will be directed _______ above the OC of the lens Correct
Answer 4mm
a frame with pantoscopic tilt is fit so that Correct Answer the
bottom of the eyewires are in closer than the top.
a frame with retroscopic tilt is fit so that Correct Answer the
bottom of the eyewires are out farther than the top
A lens containing over 1.50D of cyl must be within _____ of the
specified axis Correct Answer + or - 0.75
A lens of 7mm (.007m) thickenss has a front surface power of
+12.00D, and a back surface power of -2.00D. If the lens is
constructed of crown glass (N=1.523), what is the nominal or
total power? Correct Answer 12 + (-2)= +10
+10 + (.007/1.523) x 144
+10 + (.0046 x 144)
+10 + .66
,=10.66D
A patient has a monocular PD of OD: 31mm and OS: 33mm.
The box measurement of the frame is 52/18. Locate the major
reference point for each eye. Correct Answer Right: 4mm
inward
Left: 2mm inward
52+18=70/2=35
Right:35-31=4mm
Left:35-33=2mm
In because OC wider than PD
A patients PD was noted to be 62mm when the actual
measurement is 66mm. If the power of the lenses are -2.00D in
both eyes how much prism will be induced and in what
direction? Correct Answer Right eye: -2.00 X 2/10=0.4
Left eye: -2.00 X 2/10=0.4
Total: 0.8 base out
because OCs are more narrow than PD
A refractive error in which the rays of light do not come to a
single point of focus is called ________? Correct Answer
astigmatism
a Rx requires 2.00 Base Up, in a +5.00D lens. Where must the
MRP be located? Correct Answer 2/5=0.40cm below optical
center
or 4mm
, A Rx requires 4 base in. Rx=4.00D O.U. (4 Base In would be
equal to 2 Base In for each eye) What is the decentration
required? Correct Answer 2/4=0.50 cm or 5mm in each eye
A tendency of the eye to deviate upwards Correct Answer
hyperopia
A tendency of the visual axis to deviate inward while the eyes
are in a position of rest is known as _______? Correct Answer
esophoria
Accomodation Correct Answer the eye adjusts for viewing
objects at various distances, this is accomplished by:
1. the ciliary muscle relaxes allowing for the thickening of the
crystalline lens
2. the eyes converge
3. the pupils constrict
According to ANSI standards, a lens containing 0.25D of cyl
must be within ________ of the specified axis Correct Answer
+ or - 7.0
According to the ANSI Z80.1-1999 lens power standard, the
amount of power tolerance: Correct Answer Gets greater as
lens power increases.
According to Z80.1/1999 the horizontal prism tolerance for a
pair of mounted lenses is: Correct Answer 2/3 of a D
According to Z80.1/1999 the horizontal prism tolerance for a
pair of mounted lenses is: Correct Answer 2/3 of a D
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Classroom. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $14.99. You're not tied to anything after your purchase.