Multifocal height is usually determined by measuring from the ________.
Lower edge of the lens
The standard distance between the segments in fused double segment multifocal in most cases is:
13 mm
A semi-rimless mounting consists of:
A center piece with lens bars connecting the endpieces and temples
Most commonly, opticians use a Geneva lens measure to:
Measure lens base curve
Plastic lenses are made of a hard resin material known as :
CR-39
Corrected curve lenses have ______.
Less oblique astigmatism
To widen the distance between the pads of a frame or mounting, bend the pad arms:
Outward
A patient stops into your dispensary for an adjustment of his glasses. After careful inspection, you find the only thing wrong is that there is too much pantoscopic tilt. To make the necessary adjustment you will:
Angle the temples upward from the endpieces
Aspheric lens surfaces are most commonly used with:
Cataract lenses
Myopia is usually associated with:
A longer than normal eyeball
The most commonly used prescription for correcting muscle imbalance in extropia would be:
Base in prism
An ophthalmic correction from an ametrope is to focus parallel incident light rays at the:
Far point of the eye
The imaginary ocular plane lying on the X and Y axis is called:
Listing's Plane
What is NOT a factor in determining vertical imbalance?
The ADD power
A vertometer cannot measure or locate the ______________.
Top of a bifocal segment
A very good CR-39 lens is commonly used in cataract case is a:
Lenticular
What affects the vertex power of a lens?
Thickness
The instrument that opticians commonly use to measure vertex distance:
Distometer
If the right temple is angled down, this adjustment will:
Raise the right side of the front
If the pad arms are lengthened, this adjustment will:
Push the front out more
Image size is always increased if you:
Increase the front curve
A slab-off should be ground in the lens which was the:
Most minus power
Most aspheric surfaces are:
Spherical
A ptosis crutch is used to give support to:
Upper lid
The main reason for the use of lenticular lenses from high plus powers would be:
Lighter weight
Astigmatism is corrected by a lens having:
Cylinder power
The prism measurement indicator found in a vertometer or lensometer is called the:
Reticle
The main reason for the use of Iseikonic lenses is to:
Match image sizes
When a frame is said to have retroscopic tilt, the following condition is meant:
The bottoms of the eyewires are out further than the top
The plier best used for adjustment of rocking pads is:
Half round
When selecting a frame for a potential progressive power lens candidate, avoid the following:
Aviator shape, frame PD larger than patient PD
A reverse slab-off should be used in the eye which has the:
Most plus power
The modern lens material thought to have the most resistance to impact is called:
Polycarbonate
Bicentric grinding is synonymous with:
Slab- off
A slab-off, which is ground to reduce vertical imbalance at near, creates base _______ prism in the near portion of the lens.
Up
A reverse slab-off is molded with base ________ prism in the near portion of the lens
Down
When measuring the segment height for a progressive power lens, you should measure:
From the center of the pupil to the lowest portion of the eyewire
The "boxing method" locates the:
Geometric center of a lens
If the pad arms are bent up and the pads realigned, this adjustment will:
Drop the front
As the pantoscopic angle is increased:
The optical centers should be lowered
The type of bridge on a plastic frame designed to rest entirely on nose pads is the:
Keyhole
If the eyewire touches the cheeks, the adjustment to take care of this condition would be:
Decrease pantoscopic tilt
To widen the distance between the pads of a frame or mounting, bend the pad arms:
Outward; Angle the temples upward from the endpieces
Bowing temples in an expression referring to:
Curving temples around the head