Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
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
Normal Size Small Size show me how
ABO (NOCE) Practice
Q&A Chapters 4 & 5 Lens Material and Frames
| Question | Answer |
|---|---|
| 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
Popular Medical sets