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The frame front
- Eyewire
- bridge
- endpieces (where temples attach to the frame front)
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Temples
- butt portion
- shaft
- bend
- earpiece
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guard arms
small wire arm that holds the nose pad in place
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Cellulose acetate ("zyl")
makes up majority of plastic frames on the market. Made from cotton linters, some liquid chemicals and plasticizer.
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metal frames (monel)
nickel (65%) based metal with copper and iron
disadvantages--plating can wear off--skin allergies, heaviest of metal frame materials
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Certified 100% titanium=
at least 90% of frame is titanium with no nickel
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Plastic Frame Materials
- Cellulose Nitrate (zylonite)--FLAMMABLE
- Propionate--Lighter weight than zyl
- Optyl--Stronger and lighter than zyl, epoxy resin with thermo-elastic memory, hypoallergenic
- Nylon/Polyamide--lightweight, flexible, durable, translucent, hyperallogenic, chemical resistant
- Carbon Fiber--combined with nylon/thin, light, strong, NOT ADJUSTABLE
- Polycarbonate--sport/safety purposes
- Kevlar--combined with nylon/strong and lightweight, IMPOSSIBLE TO ADJUST
- Rubber--sports eyewear, sunglasses frames, swim goggles
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Certified Beta Titanium=
at least 70% titanium and no nickel
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Full frame
metal frame has a solid metal band that surrounds the entire lens. Lens is held in place in a groove in the eyewire, which is tightened around the lens with a screw.
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Skewing
When one lens appears higher than the other
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Bench Adjustment order
- Start at bridge and work out towards temples
- look for skewing (horizontal alignment)
- 4-point touch for vertical alignment (face form, x-ing, variant plane)
- temple spread
- temple parallelism--flat surface touch test
- pantoscopic tilt
- temple bend
- temple fold (case angle)
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5 steps to evaluate the adjustment
- Temple spread--does your PD ruler fit between the temple and side of patient's head?
- Vertex distance--is it equal? Have pt. look down, view from above
- Pantoscopic Tilt--look at patient's profile
- Level eyewires--is one side higher than the other?
- Temple bend position--look behind ears to evaluate
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Frontal angle
the vertical position of the pads when viewed from the front (should be ~20 degrees)
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