Frame Parts
This part of the frame front directly supports the frame on the patient’s nose.
Bridge
Frames are first classified based on this factor.
Material (plastic or metal)
This type of frame requires heat for lens insertion.
Plastic frame
This system uses four lines to create a box around the lens.
Boxing system
If the A measurement is much larger than the B measurement, the frame appears more…
Rectangular
his part must be opened before inserting lenses into a metal frame.
Eyewire
This plastic material is widely used because it can be produced in many colors and styles.
Cellulose acetate
This type of frame gives a “rimless look” but still uses a cord for support.
Semi rimless ( Nylon cord)
This measurement represents the maximum horizontal width of the lens.
A measurement
If A and B are equal, the frame difference is…
Zero
This part contains the hinge and connects the frame front to the temple.
Endpiece
This material replaced zylonite but can become brittle over time.
Cellulose acetate
This frame type holds lenses using screws instead of an eyewire.
Rimless mounting
This measurement is the vertical depth of the lens.
B measurement
The geometric center is located at the intersection of these two features.
Horizontal midline + vertical midpoint
In a metal frame, these components allow the frame to sit properly without touching the face fully
Adjustable nose pads
This frame material is lighter than acetate but sensitive to heat and chemicals.
Propionate
This frame combines both plastic and metal components.
Combination frame
This measurement is found by adding A + DBL.
GCD (Frame PD)
DBL is measured from this location on the frame.
Inside nasal eyewire grooves
This part includes the bend, shank, and earpiece sections.
Temple
This material returns to its original shape when reheated due to thermo-elastic properties.
Optyl
This frame type is specifically designed for near vision only and sits lower on the nose.
Half-eye frame
This measurement helps determine the smallest lens blank needed.
Effective diameter
The boxing system replaced this older measurement system.
Datum system