an optical laboratory employee you may be responsible for maintaining
the level of stock required by your laboratory for each type of frame
that you keep. To do so you have to know how to identify each item. In
this unit you will learn about the frame materials, basic parts of a frame,
different types of frames, and the storage of frames in the laboratory.
of the challenges you will face when you are locating a frame for your
customer has to do with the large number of frames available. You will
have to be sure that you get the right one. The best way to do this is
to be sure you check the following frame information: the manufacturer,
style number, style name, color, eye size, bridge and temple length. There
are hundreds of new frame styles coming out each year and it is impossible
for any person to expect to keep the details about each new frame in mind.
And since many of those frames differ only slightly, you probably won't always be able to tell by sight if you have the correct frame. So don't be in too much of a hurry as you are picking the frames. Remember,
time taken at this step in the process is better spent than the time and
money lost if you were to have the laboratory place a patient's prescription
into the wrong frame.
Frames may be stored in the stockroom in a variety of ways. In fact, each
laboratory has its own special variation on the system. But most often
there is a large collection of frame cabinets, with many small cubbyholes
holding the frames. You will find one type, color, style and size of frame
In large laboratories, there may be automatic filing systems, sometimes
referred to as "Lektrievers." The cubbyholes are shelves which
rotate when buttons are pushed. The Lektriever is tall, often rising as
high as the ceiling, and allows for more effective use of space in the
Today's frames are made of many different types of materials. Different materials
are used for style, durability, color, and ease of use but, for the most
part, frames are made from plastic and metal.
Plastic frames are available in many colors and are usually thicker and
wider than metal frames. Metal frames tend to be thinner, lightweight,
and strong. Each material has features that make it popular.
Some of the different types of plastic and metal frames, and their
" Easy to work with
" Available in many colors and styles
" Delicate material
" Used for sports
" Limited colors
" Thin profile
to work with
" Won't fracture
Basic Frame Parts
ophthalmic frames are made up from three parts: the front, a left
temple, and a right temple (see Figure 6-1). The combination frame,
which you will study later, may also be made up from a front,
called a chassis, to which trim plaques can be added.
Figure 6-1 Parts of a Basic Ophthalmic
temples are exchangeable with different front sizes and, occasionally,
with different front styles. Therefore, frames with interchangeable
fronts and temples are stocked separately. The frames
are assembled by shop personnel as part of the manufacturing procedure.
There is an increasing trend among manufacturers to
supply completely assembled frames.
The bridge of the frame front serves two functions. First, it sup-ports
the glasses on the
nose. Second, it connects the two lens
containers. The front holds the lenses in a precise orientation
before the patient's eye according to the prescription.
There are several ways to rest the front of the glasses on the nose.
nose pads may be attached to the bridge. A
special bridge insert of molded plastic, sometimes known as a form-fit
bridge, may also
be used. Finally, the bridge and nose rest area
may be integrally molded into the frame. The latter technique is
used for most plastic
frames. The bridge in plastic frames may be
further classified into the keyhole bridge and the saddle style
bridge. Figure 6-2
shows a picture of a keyhole bridge. It is called
that because it looks something like the keyhole in an old door. The
bridge contour is
not continuous; it has small cut-out sections on
either side. This means that the nose does not make continuous
contact with the front
of the frame in the area called the nasal crest.
Figure 6-2 A Frame with a Keyhole Bridge
Figure 6-3 A Frame with a Saddle Bridge
saddle bridge, shown in Figure 6-3, is also common. It allows the
nose to make continuous contact with the front of the frame.
frame has openings (or apertures) for two lenses — a right
lens and a left lens.
The left lens is the opening on the wearer's left.
The opening for the right lens is the opening on the wearer's
right. Refer back
to the illustration in Figure 6-1.
temple of the frame is the long portion that supports the frame
on the ears. It is also known as the earpiece. There are a variety
of different styles of temples. We will discuss three of the most
common ones in this course. Figure 6-4 shows the three basic types
of temple used on eyeglasses.
Note: The overall length that you will find marked on the temple is
actually the unbent
length that you see in Figure 6-4.
Figure 6-4 Three Basic Temple Styles
length is now measured in millimeters, but it used to be measured
in inches. Therefore, you may occasionally have to convert a
measure from inches to millimeters. Figure 6-5 shows a conversion
scale which you may find helpful.
Figure 6-5 Conversion Scale Inches to Millimeters
Note: Due to Monitor and Printer Variations this scale may appear different
library temple has almost no bend over the ear. Look again at Figure
6-4. This type of temple was developed for people who need to
remove and replace their glasses many times during the day, such
as someone doing research in a library, and that seems to be the
origin of the name.
most common type of temple is called the skull temple. The bent
and unbent versions of the skull temple are shown in Figure 6-4.
Look again at that figure before proceeding with this section. The skull
temple is most comfortable for those people who wear their
eyeglasses for long periods of time. It fits easily on the ear,
and bends slightly
to fit the skull and lightly hug the head. Figure 6-6
shows a picture of a frame with skull temples.
Figure 6-6 Frame with Skull Temples
third type of temple we'll consider in this course is the riding
or cable bow temple.
As you can see by looking at Figures 6-4 and 6-7,
this type of temple fits around the ear. It hugs the ear, and is
more difficult to
remove. This type of temple would be particularly helpful
for those people whose jobs are very active, or for children who
are likely to romp and play with little thought for their eye-glasses.
Figure 6-7 Frame
with Riding Bow Temple
are a few pieces of hardware found on the frame: hinges and temple
screws. A hinge
is a frame component consisting of three main parts: the two
halves of the hinge barrel and a pivot pin or screw. One barrel
half is mounted in
the frame front, the other mating barrel half is mounted
in the temple piece. The pivot pin or screw secures the two
halves of the hinge barrel together. The hinges permit the temples
to fold easily.
Plastic temples on many types of frames have a wire which runs
the middle. This core wire has been added for strength.
Types of Frames
are many different types of frames. We will study five different
types in this course.
The variations in type are based on the materials
from which the frames are made, their style, and the purpose
for which the frames are designed.
years, the most common frames were made from a cellulose acetate
material called zyl. Recently, new plastic materials have been
utilized in frame manufacture. Each has unique properties that
enhance fabrication, safety, or colorization. These materials include
epoxies, propionates and nylons. Each requires different handling
in the finish room.
metal frames, the temples and front are made of metal, except
the portion of the temple that fits the skull. Figure 6-8 shows
a metal frame. Note that this metal frame is equipped with adjustable
rocking nose pads.
Figure 6-8 Metal Frame
are some frames which provide no, or only partial, peripheral support
for the lenses. These are called rimless, or semi-rimless, frames.
Rimless frames are constructed in several different ways.
Figure 6-9 shows one type of rimless frame in which tiny screws
have been inserted through the eyeglass lens to attach the frame.
Figure 6-9 Rimless Frame
style that has become very popular requires a shallow groove
to be cut into the edge of the lenses into which a nylon cord fits.
Each end of the nylon cord is attached to the frame. The tension
in the nylon holds the lenses firmly in the mounting.
frames are made from a variety of materials and decorative parts.
These frames are called combination frames.
Figure 6-10 Combination Frame
combination frame shown in Figure 6-10 is composed of five parts.
The lenses are contained in a metal chassis; two trim over-lays
are added to the chassis
and metal or zyl temples are hinged to
the top rims. This frame uses adjustable rocking nose pads for
halfeye, or reading eyeglasses (see Figure 6-11), are only half
lenses, so that the
presbyopic emmetrope can focus on things at a distance
by looking over the lens without having to remove their eyeglasses.
Although they are less common, there are also frames designed
for the presbyopic myope to look under lenses that possess their
distance correction. This individual needs little, if any, correction
for reading, but must look through their correction to see
distant objects clearly.
Figure 6-11 The Halfeye Frame