Stuff I Can’t Get Right Flashcards
Titanium frames
Advantages: Hypoallergenic, lightweight, corrosion-proof, strong
Disadvantages: not easy to manufacture, can be labeled titanium while containing other metals
ANSI Z87.1 -2003
High Impact
- No less than 2mm thick at thinnest point
- 1/4” steel ball shot at lens at 150’/s
- Sandblasted
- Poly or Trivex
- Etched temple
Vitreous Chamber
Between retina and lens
Filled with vitreous humor
ANSI Z87.1 -2003
Basic Lenses
- 3.0mm thick (>+3.00: 2.5mm)
- 1” steel ball dropped 50”
- Sandblasted
- Must have warning label
- Etching on temple
1.7X High Index
1.70 ABBE: 36
1.74 ABBE: 33
Pros: Thickness
Cons: Cost, ABBE value
Must have AR
Posterior Chamber
Between the iris and lens
Contains aqueous humor
Macula
Small, sensitive area of the central retina, providing vision for fine work and reading
Anterior Chamber
Between the cornea and iris
Contains aqueous humor
Layers/Tunics of the Eye
1- Fibrous tunic (sclera and cornea)
2- Vascular tunic (iris, choroid, ciliary body; nourishment)
3- Nervous/Neural tunic (inner layer of photoreceptors and neurons; consists of retina)
Trivex
N=1.53
ABBE: 43-45
Pros: mid to high RX, coatings and tints, replaces poly, good/great optics
Cons: thickness rivals plastic
Papilla
Small bump where the optic nerve exits the eye
Memory Metals
Pros: Bend instead of break, return to original shape, spring-like quality, lightweight
Cons: Poorly designed, impossible to adjust, bad for asymmetrical faces
Medial Rectus
-Rotates eye towards nose
-Attaches to the eye and runs straight back
Polyamide
-Nylon
-Lightweight
-Chemical resistant
-High UV resistance
-Don’t use heat
Glass
N=1.53
ABBE: 58
Pros: scratch resistance, optics, coatings, chemical resistance
Cons: weight, safety, availability, processing time
Superior Rectus
Eye looks up
Attaches directly to eye and runs straight back
Polycarbonate
N=1.586
ABBE: 31
Pros: safety, availability, weight, high sph rx, good for children and people w/ one eye
Cons: coatings and tints, high cyl rx, ABBE value
Superior Oblique
Eye rolls, looks down, to the side
Attaches under superior rectus but follows same path
Keratoconus
Degenerative corneal disease where the center of the cornea becomes conical in shape
Fovea
Depression in the retina that contains only cones and provides acute eyesight
Optyl
Memory plastic
Can be adjusted with heat and holds shape when cooled
Aphakia
Condition of the eye with the crystalline lens removed or missing due to trauma
Aphakic Lens
Lens worn after cataract surgery when an intraocular implant is not put into the eye after removal
Base In/Base Out Prism
Patient may describe objects as being tilted
Limbus
Where the cornea and sclera join
Plastic
N= 1.49/1.50
ABBE: 58
Pros: cost, optics, coating and tints, basic rx
Cons: thickness, weight, will break if cracked or drilled
Low Power Aspheric Lens
All aspheric lenses not specifically designed for post-cataract use
Vogel’s Rule
Plus lens
- BC= spherical equivalent +6.00D
Minus lens
- BC= half spherical equivalent +6.00D
Vertex Distance
Distometer
From front of cornea to back of lens
Plus lens
- towards eye loses, away from eye gains
Minus lens
- towards eye gain, away from eye loses
1.6X High Index
ABBE: 36-42
Pros: high rx, coatings, optics
Cons: cost, inconsistent tinting, some labs won’t drill
AR
Light
Form of radiant energy
186,000m/s
Monel
Nickel based
Pros: easy to adjust, hold adjustments, strong, lightweight, wide range of colors, economical, solder
Cons: plating can wear off, prone to breaking, erodes quickly, heaviest of metal frames
