Other
ABO numbers, math, formulas (ACCURATE!!) | Optometry
- Course
- Institution
ABO numbers, math, formulas (ACCURATE!!) | Optometry Prentice's Rule High index IOR
[Show more]
Seller
Follow
smartchoices
Reviews received
Content preview
ABO numbers, math, formulas (ACCURATE!!)Prentice's Rule -answer- P = f x c
P = amount of prism correction
f = lens power (in diopters)
c = decentration (the distance between the pupil centre and the lens's optical centre, in
millimeters)
Cornea IOR -answer- 1.37
Tear Film, Vitreous IOR -answer- 1.33
Crystalline lens IOR -answer- 1.42
Optical Standard index of refraction -answer- 1.53
Crown Glass index of refraction -answer- 1.523
High index IOR -answer- 1.74
CR-39 IOR -answer- 1.49 - 1.50
Poly index of refraction -answer- 1.586
Air IOR -answer- 1.00
How fast does light travel through air -answer- 186,000 mi/sec
Minimum Blank Size (MBS) formula -answer- (GCD - PD) + ED
A + DBL + ED - PD
Frame PD - PD + ED
Dec. + ED
GCD = geometric center distance or A + DBL
PD = Pt. PD
ED = effective diameter
Dec. = Decentration
Focal length formula, diopters known -answer- 1/Dioptic Power
Dioptic Power formula, foci known -answer- 1/Focal Length (m)
Anisometropia -answer- Difference of 2 diopters between OD & OS
, What is the Radius of a 1 diopter curve? -answer- 530mm
Radius formula -answer- 530/Power = R
Power formula -answer- 530/Radius = Diop.
Vertical Decentration formula -answer- Seg.ht. - B/2
OC height - (B measurement / 2)
How much HORIZONTAL prism tolerance is allowed? -answer- 2/3 of a diopter
-or-
0.667
How much VERTICAL prism tolerance is allowed? -answer- 1/3 of a diopter
-or-
0.333
Base Curve tolerance -answer- +/-0.75
Sphere Tolerance up to 6.50 -answer- +/- 0.13
Sphere Tolerance above 6.50 -answer- +/- 2%
Cylinder Axis Tolerance >1.50 -answer- +/-2°
Cylinder Axis Tolerance >0.50 / less than or equal to 1.50 -answer- +/-3°
Cylinder Axis Tolerance >0.25 / less than or equal to 0.50 -answer- +/-7°
Cylinder Axis Tolerance >0.00 / less than or equal to 0.25 -answer- +/-14°
Drop ball test for Safety lenses -answer- 5/8ths in. diameter, weighing 0.56 oz.
dropped 50ft
Frame PD -answer- A box + DBL
Total decentration -answer- Frame PD - Patient PD
A + DBL - PD (divide by 2 to get decentration per lens)
Base IN (MINUS) -answer- If lens PD is GREATER than pt. PD
Base OUT (MINUS) -answer- If lens PD is LESS than pt. PD
Thindex glass IOR -answer- 1.8
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 smartchoices. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $10.39. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
62555 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now