Rimless Style Frames Flashcards
What does rimless mounting include?
almost any type of frame that does not have a plastic or metal rim around the lens.
What are the 3 Mounting types?
-Three-Piece Mounting
-Semi rimless Mounting
-Nylon Cord/ String/Nylon Supra
What is three-piece mounting?
A frame that has no rim at all and no connection between the bridge and end piece areas other than the lenses
What is the Semi rimless Mounting? 3
-Central bridge area attached to endpieces with metal bar
-Bal grip Mounting
-Lenses are held by spring tension using clips and notches in lenses.
What is Nylon Cord/String/Nylon Supra mounting?
Lenses which are grooved along edges and held in place with a nylon cord.
what are the 4 different lens drills?
-Non-electric hand-held
-Basic electric stand
-In-edger
-Computer-assisted
How do you use a basic stand drill? 4 steps
1)Lens is held perpendicular to the angle of the drill bit
2)the marked location for the hole is centred on the base of the drill.
3)Drill is turned on
4) slowly drill through the lens typically by a foot switch
Review Drilling chart in powerpoint
How do we use a coquilles for marking lenses ready for drilling? 3
-coquille lens is place on top and aligned with edged lens
-hole locations are sighted.
-hole locations are dotted with a felt-tipped pen.
Review the steps for attaching drilled lenses to mountings
What are slotted lenses?
Lenses that are held in place with a clip which is slipped into a slot in the lens and stays in place by a tensile spring effect.
What are notched lenses?
Lenses which are notched on either side and held in place with clips on the frame that fit into the notches.
What are the 2 methods of notching lenses?
- by hand
- with a milling bit
When notching lenses by hand what do we need to remember? 2
Most difficult method
Requires practice
What do we need to rememeber when notching with a milling bit? 2
-better results than hand notching
-lens is pressed against the side of the milling bit and after smoothed with a cone tool.
What are 2 common flaws when mounting rimless glasses?
-screws are tightened too tightly - no distortion around drill holes should be seen
-crazing- overtighting may cause this.
What is the worse material to drill and why?
Glass
Hardening and drilling the lens causes internal stress and if hit on the edge it will break.
What are the best material to use when drilling? 2
Trivex
High index plastic
Name 7 parts to a rimless
*Bridge
*Temples
*Plugs
*Bolt
*Nuts
*Hex
*Screws
What are 7 ways to reduce minus edge thickness?
1.By using a hand edger to roll the edges of the minus lens.
2.Keep the A and B as small as possible.
3.Round lens shape
4.Patient PD to make Frame PD so little decentration is needed.
5.Use high index material
6.Polish edges
7.Use an antireflection coating
Why is it important for the lenses to be drilled in the exact right location? 5
1.Axis might be off in spherocylindrical lenses
2.Uneven Parallelism
3.Misaligned frames
4.Skewed appearance
5.Lenses may not align where the patients OC is located.
