Busy. Please wait.

show password
Forgot Password?

Don't have an account?  Sign up 

Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Didn't know it?
click below
Knew it?
click below
Don't know
Remaining cards (0)
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

ABO (NOCE) Practice

Q&A Chapters 4 & 5 Lens Material and Frames

What is the index of rafraction for CR-39 plastic? 1.498
What is the index of refraction of Crown Glass? 1.52
What is the Abbe number of Cr-39? 58
What is the specific gravity of Crown Glass? 2.54
What is the specific gravity of CR-39? 1.32
What is the Abbe number for Crown Glass? 58
What is the index of refraction for Polycarbonate? 1.59
What is the specific gravity of Polycarbonate? 1.20
What is the Abbe number for Polycarbonate? 31
What does Aspheric mean in the optical world? non-spherical
Bicentric grinding or "____ ___" is one way to correct for vertical imbalance slab off
"____________ ____ ___" is always ground base up on the lens with the most minus or at least plus power in the 90 degree meridian. Conventional Slab Off
What does "PD" stand for? Pupillary Distance
The average person's eyes will converge _ to _ mm inward to read 3 to 6
"_________ __" is the distance from the center of the bridge of the nose to the center of each pupil. The right eye is recorded first then the left eye. (example: 33/34) Monocular PD
What does OCHt stand for? Optical Center Height
Bifocals and Trifocals need _______ height. segment
Progressives lenses need _________ OCHt monocular
"_______ ______" is measured from the lower eyelid to the deepest B portion of the eye wire. Segment Height
"_____ _______" bend down behind the ear and follow the contour of the skull, resting evenly against it. Skull Temples
"_______ _______" generally straight and hold the spectacles on primarily by pressure against the side of the head. Library Temples
"______ ___ _______" curve around the ear and extend to the level of the ear lobe. They are often used in both children's frames and safety eyewear. Riding Bow Temples
"___________ _______" can be used either as library or skull temples depending on the manner in which they are bent. Convertible Temples
An imaginary line is drawn through the middle of the eyewire both in the horizontal and vertical planes. What is the name of this process? The Datum System
An imaginary box is drawn around the are to be measure. What is the name of this process? The Box System
Horizontal measurement of the box enclosing lens area, also known as the eye size. What is the name of this measurement? A
The least distance between the two lenses. This is known as the... DBL
Vertical measurement of the box enclosing lens area. What is the name of this measurement? B
The difference between the horizontal and vertical measurements is known as the... Frame Difference
Twice the distance from the geometrical center of the lens to the bevel farthest away from it. This is known as the... Effective Diameter
The width of the lens along the central datum line. This is known as what measurement? C
The measurement from the center of the barrel to the middle of the bend is called the ______ __ ____. length to bend
The amount of ____________ required in each eyeis equal to the (GCD - PD)/2 decentration
It is necessary to calculate ________ ____________ when determining where the line or fitting cross of a multifocal lens is positioned relative to the datum line of the frame. vertical decentration
Name this frame material: Epoxy material. Light in weight, cannot be overheated or burned and will not shrink. Optyl
Name this frame material: Originally the most used material for frames, it is a cotton/wood flak product and can be produced in a great variety of colors, textures and patterns. Zyl
Name this frame material: Synthetic material made from coal, water and air. Light in weight and very strong. Often used in childrens frames. Nylon
What are the two types of materials frame are made of? Metal and Plastic
Name this frame material: Noncorrosive, strong and light in weight. Often used in temples. Stainless Steel
Name this frame material: Light in weight, long lasting, may be anodized allowing for many variations in color. Aluminum
This face shape can wear most frames well. Oval
This face shape should wear relatively narrow frames preferably with high temple attachments. Round
This face shape should wear a deep frame, preferably with low temple attachments. Oblong
For ___________ wearers: Frames with adjustable nose pads or minimal vertex distance. Slight face form and avoid radical nasal cutaways. progressive
For ________: Safety is the first and foremost consideration. A well fit bridge and spring hinges for flexibility. children
For ______: Lenses must be 3.00mm thick. "Z87" markings on each temple and the frame front. safety
A well fit frame will come in contact with the wearer only at the following three points known as the _______ ________ fitting triangle
There should be 8-10 degrees of ___________ ____ for most frames. pantoscopic tilt
Less commonly, when the pupil is positioned directly behind the optical center, an ___________ ____ is recommended. orthoscopic tilt
In the very unusual situation where the pupil is positioned below the optical center of the lens, a ___________ ____ is called for. retroscopic tilt
Most frames will have some ________ face form. positive
The need to apply ________ face form can usually be avoided with more appropriate frame selection. negative
Left lens is farther out - Bend left end piece ___ out
Left lens is farther in - Bend left end piece ___ in
Increase pantoscopic angle - Bend both temples or end pieces ___ down
Decrease pantoscopic angle - Bned both temples or end pieces ___ up
Created by: burukkusu



Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards