OL1 TP2 Spectacle Frames

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  • Created by: Davina1st
  • Created on: 23-04-23 12:33
Supra (semi-rimless) spectacles
Lenses held in position by thin bands or cords attached to the rims
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Clip on spectacles
Attachment holding an auxiliary lens or lenses in front of the spectacles by spring action or hooks/magnets
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Half-eye spectacles
Usually for reading: shallow, high bridge, longer sides
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Lorgnette
Eyeglasses for occasional use, held before the eyes by a handle into which the one or two lenses may fold when not in use
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Pinz (pince) Nez
To pinch the nose, no sides
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Saddle bridge
shaped to rest on the nose over a continuous area, but the end of the surface extends to lie behind the back plane of the front
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Arch and crest
Arch = main curve of the bridge forming the bearing surface. Crest = the central portion of the arch
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The lug
part of the frame extending from the rim to which the joint is attached
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Joint hinge
The hinge linking the side and front
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Sprung joint
joint having a spring mechanism to exert lateral pressure on the side of the head by the spectacle wearer
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Closing block joint
joint which enables a metal rim to be closed with a screw
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Sinuous side
A drop-end side in which the cnetral line describes one or more curves from the dowel point to the bend
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What are the three lens shapes?
round, oval or half eye
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Pilot/aviator
Family of lens shapes, characterised by nasal cut-away and pronounced fullness in the lower temporal quadrant
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Quadra shape
family of lens shapes, four recognisable sides of shallow curvature, joined by arcs of shorter radius
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Upswept shape
upper edge has a marked upwards slope to the temple
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3 traditional bio based material
Leather, bone (fish and mammal), tortoise shell
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Bio based current materials
wood, and horn (ethical by product of farming), caster seed oil (caster beans), natural acetate (composition of cotton and wood)
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Pros of bio based materials
Hypoallergenic, renewable, cosmetically appealing
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Cons of bio based materials
Specialist craftspeople, cost, difficult to adjust
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Name 3 type of thermoplastics
cellulose nitrate, cellulose acetate, cellulose propionate, TR90
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Pros of cellulose nitrate
Tough, high shine, retains its shape and stability even in hot and humid conditions
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Cons of cellulose nitrate
Brittle and yellows with age, not hypoallergenic, flammable so illegal
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What is cellulose acetate?
Non flammable, block form=cut out of sheets, extruded=moudled (stronger frame). Coloured by adding water based dyes, frames often finished with acrylic lacquer to improve scratch resistance. frame sided reinforced with metal.
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Pros of cellulose acetate
Relatively cheap, easy to manufacture, easy to adjust, easy to colour
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Cons of cellulose acetate
Some people are allergic, may bubble and blister when heated during adjustment, lacks elastic memory (dimensionally unstable), Discolours with age
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Pros of cellulose propionate
Lighter, stronger, frames can be even thinner, more flexible, more resistant to warping, more resistant to fading
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Cons of cellulose propionate
prone to damage from acetone, not hypoallergenic
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What is TR90?
often used for children's frames, rubber like texture
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Pros of TR90
Durable, flexible, lightweight, chemical and crush resistant, hypoallergenic
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Cons of TR90
Can be difficult to adjust (may have different endpieces)
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What is Optyl (epoxy resin)?
Thermosetting plastic, sets permanently when heated, elastic memory. Injection moulded, then dyed and lacquered.
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Pros of optyl
Lightweight, hypoallergenic, good plastic memory
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Cons of optyl
Hard to adjust, brittle when cold
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What is SPX (polyamide)?
Frame material, plastic, injection moulded then dyed and lacquered
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Pros of SPX
lightweight, high impact resistance, hypoallergenic, more scratch resistant
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Cons of SPX
Difficult to adjust, can shrink under intense heat, brittle when cold
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What is carbon fibre?
Plastic, not 100% carbon fibre, has to be wrapped in a thin polymer sheet to colour
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Pros of carbon fibre
Lightweight, strong, flexible, robust, hypoallergenic
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Cons of carbon fibre
Difficult to adjust, expensive
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What is carbon nylon?
frame front with matching metal sides, 20% carbon fibre, 80% nylon, injection moulded, naturally grey so colour coating is required
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Pros of carbon nylon
Lightweight, strong, flexible, hypoallergenic
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Cons of carbon nylon
Cannot heat as leaves fingerprints in material
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Pros of gold metal
hypoallergenic, unaffected by temperature, acid resistant
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Cons of gold metal
heavy, bends easily (soft), more often gold plated = expensive
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What is rolled gold?
Gold layer bonded to mixed metal base, quality/quantity can vary, 100x more gold than gold plated, should have a stamp.
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Pros and cons of rolled gold
easily repaired, hypoallergenic, expensive
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Pros of titanium metal
strong, flexible, hypoallergenic, resistant to corrosion and perspiration, lightweight, can be coloured by plating
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cons of titanium metal
production costs are high
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Pros of aluminium metal
Lightweight, strong, stain and corrosion resistant, coloured by plating (electrolysis)
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Cons of aluminium metal
Cannot be soldered/ riveted, highly rigid so glazing and adjustment difficult, cold to touch, not hypoallergenic
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Pros of stainless steel metal
lightweight, strong, flexible, resistant to corrosion and perspiration
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Cons of stainless steel
Not hypoallergenic
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Pros of nickel silver metal alloys
relatively cheap, sturdy/robust, easy to solder
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Cons of nickel silver metal alloys
many people allergic to nickel, dulls quickly
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Pros of memory metals
can be crushed, twisted or bent, lightweight flexible and strong
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Cons of memory metals
cannot be repaired, not completely memory metal, care with lens choice, not hypoallergenic
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Is a smaller or larger frame preferred for those with a high optical prescription?
smaller frame, lens=thicker and heavier as power increases, minimise decentration, pupil closer to boxed centre and reduced MSU
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Other cards in this set

Card 2

Front

Clip on spectacles

Back

Attachment holding an auxiliary lens or lenses in front of the spectacles by spring action or hooks/magnets

Card 3

Front

Half-eye spectacles

Back

Preview of the front of card 3

Card 4

Front

Lorgnette

Back

Preview of the front of card 4

Card 5

Front

Pinz (pince) Nez

Back

Preview of the front of card 5
View more cards

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