ABO, ABO Study Guide – Complete With Solutions
Prentice Rule Right Ans - (Power x distance in mm) /10
Cornea index of refraction Right Ans - 1.37
Tear Film, Vitreous index of refraction Right Ans - 1.33
Crystalline lens index of refraction Right Ans - 1.42
Optical Standard index of refraction Right Ans - 1.53
Crown Glass index of refraction Right Ans - 1.523
High index of refraction Right Ans - 1.74
CR-39 index of refraction Right Ans - 1.49/1.50
Poly index of refraction Right Ans - 1.586
Air Right Ans - 1.00
How fast does light travel through air Right Ans - 186,000 mi/sec
MBS formula Right Ans - ED+2 (decentration)+2
Focal length formula Right Ans - 1/Dioptic Power power
Dioptic Power formula Right Ans - 1/Focal Length
Antimetropia Right Ans - Rx with unlike signs in both eyes
Anisometropia Right Ans - Difference of 2 diopters btwn OD & OS
Anisiekonia Right Ans - When images from right and left eye are so
different the brain can not achieve fusion
What is the Radius of a 1 diopter curve? Right Ans - 530mm
, Radius formula Right Ans - 530/Power = Radius
Power formula Right Ans - 530/Radius = Power
Vertical Decentration formula Right Ans - Seg.ht. - B/2
How much HORIZONTAL prism tolerance is allowed? Right Ans - 2/3 of a
diopter
-or-
0.667
How much VERTICAL prism tolerance is allowed? Right Ans - 1/3 of a
diopter
-or-
0.333
Base Curve tolerance Right Ans - +/-0.75
Sphere Tolerance up to 6.50 Right Ans - +/- 0.13
Sphere Tolerance above 6.50 Right Ans - +/- 2%
Cylinder Tolerance >1.50 Right Ans - +/-2°
Cylinder Tolerance >0.50 / less than or equal to 1.50 Right Ans - +/-3°
Cylinder Tolerance >0.25 / less than or equal to 0.50 Right Ans - +/-7°
Cylinder Tolerance >0.00 / less than or equal to 0.25 Right Ans - +/-14°
Drop ball test for Safety lenses Right Ans - 5/8ths in diameter, weighing
0.56oz dropped 50ft
Frame PD Right Ans - A box + DBL
Total decentration Right Ans - Frame PD - Patient PD
Base IN (MINUS) Right Ans - If frame PD is GREATER than customer PD
Prentice Rule Right Ans - (Power x distance in mm) /10
Cornea index of refraction Right Ans - 1.37
Tear Film, Vitreous index of refraction Right Ans - 1.33
Crystalline lens index of refraction Right Ans - 1.42
Optical Standard index of refraction Right Ans - 1.53
Crown Glass index of refraction Right Ans - 1.523
High index of refraction Right Ans - 1.74
CR-39 index of refraction Right Ans - 1.49/1.50
Poly index of refraction Right Ans - 1.586
Air Right Ans - 1.00
How fast does light travel through air Right Ans - 186,000 mi/sec
MBS formula Right Ans - ED+2 (decentration)+2
Focal length formula Right Ans - 1/Dioptic Power power
Dioptic Power formula Right Ans - 1/Focal Length
Antimetropia Right Ans - Rx with unlike signs in both eyes
Anisometropia Right Ans - Difference of 2 diopters btwn OD & OS
Anisiekonia Right Ans - When images from right and left eye are so
different the brain can not achieve fusion
What is the Radius of a 1 diopter curve? Right Ans - 530mm
, Radius formula Right Ans - 530/Power = Radius
Power formula Right Ans - 530/Radius = Power
Vertical Decentration formula Right Ans - Seg.ht. - B/2
How much HORIZONTAL prism tolerance is allowed? Right Ans - 2/3 of a
diopter
-or-
0.667
How much VERTICAL prism tolerance is allowed? Right Ans - 1/3 of a
diopter
-or-
0.333
Base Curve tolerance Right Ans - +/-0.75
Sphere Tolerance up to 6.50 Right Ans - +/- 0.13
Sphere Tolerance above 6.50 Right Ans - +/- 2%
Cylinder Tolerance >1.50 Right Ans - +/-2°
Cylinder Tolerance >0.50 / less than or equal to 1.50 Right Ans - +/-3°
Cylinder Tolerance >0.25 / less than or equal to 0.50 Right Ans - +/-7°
Cylinder Tolerance >0.00 / less than or equal to 0.25 Right Ans - +/-14°
Drop ball test for Safety lenses Right Ans - 5/8ths in diameter, weighing
0.56oz dropped 50ft
Frame PD Right Ans - A box + DBL
Total decentration Right Ans - Frame PD - Patient PD
Base IN (MINUS) Right Ans - If frame PD is GREATER than customer PD
