ABO ADVANCED CERTIFICATION
SCRIPT 2026 QUESTIONS WITH
SOLUTIONS GRADED A+
◍ Resolving Prism=.
Answer: Vertical = (prism)(sin angle) Horizontal = (prism) (cos angle)
◍ Base Curve.
Answer: Curvature of the front of the lens
◍ Resultant Prism=.
Answer: The square root of (Vertical prism^2) + (Horizontal prism^2)tan
a=V/H
◍ How is Cyl ground on a minus cyl lens?.
Answer: Single curve on the front. Cyl ground on the back
◍ Shape Factor=.
Answer: 1/1-(T/NxF)T=center thickness in mN= index of refraction of lens
materialF= front base curve
◍ Power Factor=.
Answer: 1/1-(HxD)H= vertex distance plus 3 mm in mD= Dioptric power
◍ How is cyl ground on a plus cyl lens?.
Answer: Flattest curve on the front. Old way of doing it do to cosmetics
◍ What is Vogels formula used for?.
Answer: Creating best form and n standard surfacing
◍ Spectacle Magnification=.
Answer: shape factor x power factor 1/ 1-(T/NxF) x 1/1-(HxD)
◍ Power in Oblique Meridians=.
, Answer: Total power = sphere power + cyl power x sin^2 (O)
◍ Snell's Law=.
Answer: N1 sin i = N2 sin rN1= index of refraction of incident medium i=
angle of incidenceN2= index of refraction of refracting mediumr= angle of
refraction
◍ Angle of reflection=.
Answer: angle I= angle rI= angle of incidencer= angle of reflection
◍ Vogel's Formula (+ lenses).
Answer: Spherical equivalent + 6.00
◍ Angle of incidence=.
Answer: I=r+dI= angle of incidencer= angle of refractiond= deviation
◍ Index of refraction=.
Answer: Speed of light in a vacuum/Speed of light in the medium
◍ Vogel's Formula (- lenses).
Answer: Spherical equivalent + 6.
◍ Corrected Curve Theory rules:.
Answer: #1 ocular curves (minus side) that fall between -4.00 - -7.00 are
best for delivering non abbe rated vision#2 -as minus increases BC should
flatten- as plus increases BC should steepen
◍ What are the 2 base curves every lens has?.
Answer: Nominal - general category (ex. 4.25 or 6.00)Actual/True curve-
real measured curve/sag depth
◍ Prentice Rule=.
Answer: Prism= (hxd)/10h=distance moved in mmD= total dioptric power
for the meridian
◍ Thick Lens Back Vertex Power=.
Answer: De= D1+D2+ (t/n x D1^2)De= effective, vertex or lensometer
powerD1= true power of the front curveD2= ture power of the back curvet=
lens thickness in metersn= index of refraction
, ◍ Index of refracting formula.
Answer: Speed of light in air/speed of light in material
◍ Speed of light in air?.
Answer: 186,000 miles per second
◍ Flint glass index of refraction and abbe value.
Answer: 1.58-1.69 & 30-40
◍ Focal length.
Answer: D=1/fD= dioptric powerf= focal length in meters
◍ Barium glass index of refraction and abbe value.
Answer: 1.51-1.616 & 55-59
◍ Highlite glass index of refraction and abbe value.
Answer: 1.70 & 32
◍ Dioptric formula.
Answer: f=1/DD= dioptric powerf= focal length in meters
◍ CR39 index of refraction and abbe value.
Answer: 1.49 & 58
◍ Vertex power compensation (if the wearing vertex is less than the refractive
vertex)=.
Answer: Fb= (Fa)/ 1-(dFa)Fa= primary focal length of the refractive
vertexFb= Compensated powerd= distance in meters that the lens is moved
from the refractive vertex to the wearing vertex
◍ Vertex power compensation (if the wearing vertex is more than the
refractive vertex)=.
Answer: Fb= (Fa)/ 1+(dFa)Fa= primary focal length of the refractive
vertexFb= Compensated powerd= distance in meters that the lens is moved
from the refractive vertex to the wearing vertex
◍ What is the vertex power compensation for a low powered lens?.
Answer: Per mm= (D^2)/1000D= dioptric power
SCRIPT 2026 QUESTIONS WITH
SOLUTIONS GRADED A+
◍ Resolving Prism=.
Answer: Vertical = (prism)(sin angle) Horizontal = (prism) (cos angle)
◍ Base Curve.
Answer: Curvature of the front of the lens
◍ Resultant Prism=.
Answer: The square root of (Vertical prism^2) + (Horizontal prism^2)tan
a=V/H
◍ How is Cyl ground on a minus cyl lens?.
Answer: Single curve on the front. Cyl ground on the back
◍ Shape Factor=.
Answer: 1/1-(T/NxF)T=center thickness in mN= index of refraction of lens
materialF= front base curve
◍ Power Factor=.
Answer: 1/1-(HxD)H= vertex distance plus 3 mm in mD= Dioptric power
◍ How is cyl ground on a plus cyl lens?.
Answer: Flattest curve on the front. Old way of doing it do to cosmetics
◍ What is Vogels formula used for?.
Answer: Creating best form and n standard surfacing
◍ Spectacle Magnification=.
Answer: shape factor x power factor 1/ 1-(T/NxF) x 1/1-(HxD)
◍ Power in Oblique Meridians=.
, Answer: Total power = sphere power + cyl power x sin^2 (O)
◍ Snell's Law=.
Answer: N1 sin i = N2 sin rN1= index of refraction of incident medium i=
angle of incidenceN2= index of refraction of refracting mediumr= angle of
refraction
◍ Angle of reflection=.
Answer: angle I= angle rI= angle of incidencer= angle of reflection
◍ Vogel's Formula (+ lenses).
Answer: Spherical equivalent + 6.00
◍ Angle of incidence=.
Answer: I=r+dI= angle of incidencer= angle of refractiond= deviation
◍ Index of refraction=.
Answer: Speed of light in a vacuum/Speed of light in the medium
◍ Vogel's Formula (- lenses).
Answer: Spherical equivalent + 6.
◍ Corrected Curve Theory rules:.
Answer: #1 ocular curves (minus side) that fall between -4.00 - -7.00 are
best for delivering non abbe rated vision#2 -as minus increases BC should
flatten- as plus increases BC should steepen
◍ What are the 2 base curves every lens has?.
Answer: Nominal - general category (ex. 4.25 or 6.00)Actual/True curve-
real measured curve/sag depth
◍ Prentice Rule=.
Answer: Prism= (hxd)/10h=distance moved in mmD= total dioptric power
for the meridian
◍ Thick Lens Back Vertex Power=.
Answer: De= D1+D2+ (t/n x D1^2)De= effective, vertex or lensometer
powerD1= true power of the front curveD2= ture power of the back curvet=
lens thickness in metersn= index of refraction
, ◍ Index of refracting formula.
Answer: Speed of light in air/speed of light in material
◍ Speed of light in air?.
Answer: 186,000 miles per second
◍ Flint glass index of refraction and abbe value.
Answer: 1.58-1.69 & 30-40
◍ Focal length.
Answer: D=1/fD= dioptric powerf= focal length in meters
◍ Barium glass index of refraction and abbe value.
Answer: 1.51-1.616 & 55-59
◍ Highlite glass index of refraction and abbe value.
Answer: 1.70 & 32
◍ Dioptric formula.
Answer: f=1/DD= dioptric powerf= focal length in meters
◍ CR39 index of refraction and abbe value.
Answer: 1.49 & 58
◍ Vertex power compensation (if the wearing vertex is less than the refractive
vertex)=.
Answer: Fb= (Fa)/ 1-(dFa)Fa= primary focal length of the refractive
vertexFb= Compensated powerd= distance in meters that the lens is moved
from the refractive vertex to the wearing vertex
◍ Vertex power compensation (if the wearing vertex is more than the
refractive vertex)=.
Answer: Fb= (Fa)/ 1+(dFa)Fa= primary focal length of the refractive
vertexFb= Compensated powerd= distance in meters that the lens is moved
from the refractive vertex to the wearing vertex
◍ What is the vertex power compensation for a low powered lens?.
Answer: Per mm= (D^2)/1000D= dioptric power
