Quick Quiz Flashcards
To what does a pros is crutch give support?
Upper Lid
A lens focal length can be altered by?
Changing the curvature of one surface
Which instrument measures vertex distance ?
Disometer
What controls the amount of light that enters the eye?
Iris
Which word is used to describe lights changing direction as it passes from one medium to another?
Refraction
Frame materials are available in which two forms?
Metal and plastic
Meniscus equiconacve and flat concave are types of
Minus lenses
What is the term used to describe the eyes tendency to turn from its normal position?
Phoria
What is the refractive condition in which light focus directly on the retina?
Emmetropia
What is the refractive condition in which light touches directly on the retina?
Emmetropia
What kind of lens has on convex and one concave surface?
Meniscus
What material has the most favorable optical properties
Crown glass
What’s the best lens treatment to reduce water and road surface glare?
Polarized
Which private agency is responsible for establishing commercial and industry standards
ANSI
Which Fran adjustment lowers the front of the frame?
Spreading the arms further apart
The hard resin material used in plastic lenses is known as
CR-39
Which lens characteristics corrects astigmatism
Cyl power
A pt with astigmatisms has a __________ cornea
Misshapen
A polariscope is used to detect internal lens stress
True
Axis is the notation of power on a lens
False
Aphasia is
The absence of crystalline lens
Which of the following is an advantage to a titanium frame?
Corrosion resistant
The cornea index of refraction is
1.37
Which term is used to describe the outward inclination of the bottom of a framed lens?
Retroscopic
Equiconvex lens
Biconvex lens if both surface are convex
