click below
click below
Normal Size Small Size show me how
ABO (NOCE) Practice
Q&A Chapter 3 Lens Form & Analysis
Question | Answer |
---|---|
The shorter the radius the _______ the curve and the stronger the diopter power is. | steeper |
The larger the sphere the _______ the curve. | flatter |
The smaller the sphere the _______ the curve. | steeper |
A lens that is both concave and convex is known as a ________ lens | meniscus |
A concave lens is known as a _____ lens | minus |
A convex lens is known as a ____ lens | plus |
What is another name for a bi-concave lens? | Myodisc |
Distortions inherent in any lens with power are known as... | Aberrations |
What optical tool is used to measure the curvature of a lens and is considered one of the most useful but underrated tools in the optical industry. | The Lens Clock |
The Lens Clock is calibrated for what index of refraction? (the number not the name) | 1.53 |
True or False: The Lens Clock can check for slab off. | True |
True or False: The Lens Clock can determine what the lens material is made out of. | False |
What is the "standard" index of refraction in the optical industry? | 1.53 |
The cylinder is used for the correction of ___________ and can be used by itself or it can be combined with a sphere. | astigmatism |
What is the name of the term for when the distance of the ocular or back surface of a lens is away from the patient's cornea? | Vertex Distance |
A +10.00 lens has moved away from a patient's eyes by 5mm. What is the power of the lens for the patient now? | +10.50 |
A -10.00 lens has been moved closer to a patient's eyes by 5mm. What is the power of the lens for the patient now? | -10.50 |
A +10.00 lens has moved closer to a patient's eyes by 5mm. What is the power of the lens for the patient now? | +9.50 |
A -10.00 lens has been moved away from a patient's eyes by 5mm. What is the power of the lens for the patient now? | -9.50 |
What does RVD stand for? | Refracted Vertex Distance |
What does FVD stand for? | Fitted Vertex Distance |
True or False: A distometer can accurately measure vertex distance. | True |
True or False: A distometer can measure lens thickness. | False |
Vertex distance compensation is mandatory for a spectacle prescription of ______ diopters or greater. | +/- 7.00 |
What is the Base Curve for the power ranges of Plano to +2.00 | +6.00 |
What is the Base Curve for the power ranges of -2.00 to -4.50 | +4.00 |
What is the Base Curve for the power ranges of +5.50 to +8.75 | +10.00 |
In modern medical ophthalmic lenses, ocular curves are always ______ or ________ | minus concave |
A smaller sphere will have ____ power. | more |
A larger sphere will have ____ power. | less |
A flatter base curve will make objects appear _______ than before. | smaller |
An increase in plus power in the base curve makes objects appear ______ than before. | larger |
Higher index materials create lenses with natural _______ base curves. | flatter |