ABO, ABO Study Guide with Complete Solutions
Prentice Rule - -(Power x distance in mm)
/10
Antimetropia - -Rx with unlike signs in both
eyes
Cornea index of refraction - -1.37
Anisometropia - -Difference of 2 diopters
Tear Film, Vitreous index of refraction - - btwn OD & OS
1.33
Anisiekonia - -When images from right and
Crystalline lens index of refraction - -1.42 left eye are so different the brain can not achieve
fusion
Optical Standard index of refraction - -1.53
What is the Radius of a 1 diopter curve? - -
530mm
Crown Glass index of refraction - -1.523
Radius formula - -530/Power = Radius
High index of refraction - -1.74
Power formula - -530/Radius = Power
CR-39 index of refraction - -1.49/1.50
Vertical Decentration formula - -Seg.ht. -
Poly index of refraction - -1.586 B/2
Air - -1.00 How much HORIZONTAL prism tolerance is
allowed? - -2/3 of a diopter
-or-
0.667
How fast does light travel through air - -
186,000 mi/sec
How much VERTICAL prism tolerance is
allowed? - -1/3 of a diopter
MBS formula - -ED+2 (decentration)+2
-or-
0.333
Focal length formula - -1/Dioptic Power
power
Base Curve tolerance - -+/-0.75
Dioptic Power formula - -1/Focal Length
, ABO, ABO Study Guide with Complete Solutions
Sphere Tolerance up to 6.50 - -+/- 0.13 Which area of the retina is capable of perceiving
the greatest amount of detail? - -Fovea
centralis
Sphere Tolerance above 6.50 - -+/- 2%
Tonometer - -Used for intraocular pressure
Cylinder Tolerance >1.50 - -+/-2°
What is another name for Lensometer? - -
Cylinder Tolerance >0.50 / less than or equal to Focimeter
1.50 - -+/-3°
Thickest layer of the cornea - -Stroma
Cylinder Tolerance >0.25 / less than or equal to
0.50 - -+/-7°
What is the main focusing structure of the eye -
-Ciliary process
Cylinder Tolerance >0.00 / less than or equal to
0.25 - -+/-14°
Emetropic - -Perfect Vision
Drop ball test for Safety lenses - -5/8ths in
diameter, weighing 0.56oz dropped 50ft Ametropic - -Needs correction
Frame PD - -A box + DBL Thindex glass - -1.8
Total decentration - -Frame PD - Patient High light glass - -1.74
PD
Flint glass - -1.69
Base IN (MINUS) - -If frame PD is
GREATER than customer PD
3 eye layers/tunics - -Layer #1- Protective
Layer #2- Nourishing
Base OUT (MINUS) - -If frame PD is LESS Later #3- Light Sensitive
than customer PD
Cellulose Acetate (Zyle) - -Non-flammable,
Which layer of the cornea is highly regenerative? durable, avail in diff colors
- -Epithelium
Layer #1 - -Sclera, Cornea, Anterior
Prentice Rule - -(Power x distance in mm)
/10
Antimetropia - -Rx with unlike signs in both
eyes
Cornea index of refraction - -1.37
Anisometropia - -Difference of 2 diopters
Tear Film, Vitreous index of refraction - - btwn OD & OS
1.33
Anisiekonia - -When images from right and
Crystalline lens index of refraction - -1.42 left eye are so different the brain can not achieve
fusion
Optical Standard index of refraction - -1.53
What is the Radius of a 1 diopter curve? - -
530mm
Crown Glass index of refraction - -1.523
Radius formula - -530/Power = Radius
High index of refraction - -1.74
Power formula - -530/Radius = Power
CR-39 index of refraction - -1.49/1.50
Vertical Decentration formula - -Seg.ht. -
Poly index of refraction - -1.586 B/2
Air - -1.00 How much HORIZONTAL prism tolerance is
allowed? - -2/3 of a diopter
-or-
0.667
How fast does light travel through air - -
186,000 mi/sec
How much VERTICAL prism tolerance is
allowed? - -1/3 of a diopter
MBS formula - -ED+2 (decentration)+2
-or-
0.333
Focal length formula - -1/Dioptic Power
power
Base Curve tolerance - -+/-0.75
Dioptic Power formula - -1/Focal Length
, ABO, ABO Study Guide with Complete Solutions
Sphere Tolerance up to 6.50 - -+/- 0.13 Which area of the retina is capable of perceiving
the greatest amount of detail? - -Fovea
centralis
Sphere Tolerance above 6.50 - -+/- 2%
Tonometer - -Used for intraocular pressure
Cylinder Tolerance >1.50 - -+/-2°
What is another name for Lensometer? - -
Cylinder Tolerance >0.50 / less than or equal to Focimeter
1.50 - -+/-3°
Thickest layer of the cornea - -Stroma
Cylinder Tolerance >0.25 / less than or equal to
0.50 - -+/-7°
What is the main focusing structure of the eye -
-Ciliary process
Cylinder Tolerance >0.00 / less than or equal to
0.25 - -+/-14°
Emetropic - -Perfect Vision
Drop ball test for Safety lenses - -5/8ths in
diameter, weighing 0.56oz dropped 50ft Ametropic - -Needs correction
Frame PD - -A box + DBL Thindex glass - -1.8
Total decentration - -Frame PD - Patient High light glass - -1.74
PD
Flint glass - -1.69
Base IN (MINUS) - -If frame PD is
GREATER than customer PD
3 eye layers/tunics - -Layer #1- Protective
Layer #2- Nourishing
Base OUT (MINUS) - -If frame PD is LESS Later #3- Light Sensitive
than customer PD
Cellulose Acetate (Zyle) - -Non-flammable,
Which layer of the cornea is highly regenerative? durable, avail in diff colors
- -Epithelium
Layer #1 - -Sclera, Cornea, Anterior
