ABO ADVANCED EXAM | COMPLETE QUESTIONS
AND CORRECT ANSWERS | 2026 UPDATE
• Base Curve -✓✓ Curvature of the front of the lens
• How is Cyl ground on a minus cyl lens? -✓✓ Single curve on the front. Cyl
ground on the back
• How is cyl ground on a plus cyl lens? -✓✓ Flattest curve on the front. Old way of
doing it do to cosmetics
• What is Vogels formula used for? -✓✓ Creating best form and n standard
surfacing
• Vogel's Formula (+ lenses) -✓✓ Spherical equivalent + 6.00
• Vogel's Formula (- lenses) -✓✓ Spherical equivalent + 6.
• Corrected Curve Theory rules: -✓✓ #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? -✓✓ Nominal - general category (ex.
4.25 or 6.00)
Actual/True curve- real measured curve/sag depth
,• Index of refracting formula -✓✓ Speed of light in air/speed of light in material
• Speed of light in air? -✓✓ 186,000 miles per second
• Flint glass index of refraction and abbe value -✓✓ 1.58-1.69 & 30-40
• Barium glass index of refraction and abbe value -✓✓ 1.51-1.616 & 55-59
• Highlite glass index of refraction and abbe value -✓✓ 1.70 & 32
• CR39 index of refraction and abbe value -✓✓ 1.49 & 58
• Poly index of refraction and abbe value -✓✓ 1.59 & 30-32
• Trivex index of refraction and abbe value -✓✓ 1.53 & 43-45
• 5 categories of absorptive lenses -✓✓ 1- tinted solid glass
2- glass w/surface coatings
3- tinted plastic
4- photochromic
5- polarized
• Absorption definition -✓✓ Reduction of transmission of radiant energy through a
medium
, • Transmission definitions -✓✓ Transit or passing if radiant energy through a
medium
• Grey tint characteristics -✓✓ Most popular
Least amount of color change
• Brown tint characteristics -✓✓ Uses yellow to increase contrast
Good for hazy days
• Yellow tint characteristics -✓✓ Can be added to any color to increase contrast
Filters out blue light
• Green tint characteristics -✓✓ Good color balance w/better contrast than grey
Transmission curve closes to the human eye
• Pink/rose tint characteristics -✓✓ Reduces glare and softens bright light
situations
• Blue tint characteristics -✓✓ Causes glare by promoting blue spectrum
• Vaccum coatings used for: -✓✓ Mirrors and depositing uniform color on glass
lenses
• Term for snow blindness -✓✓ Photokeratitis
AND CORRECT ANSWERS | 2026 UPDATE
• Base Curve -✓✓ Curvature of the front of the lens
• How is Cyl ground on a minus cyl lens? -✓✓ Single curve on the front. Cyl
ground on the back
• How is cyl ground on a plus cyl lens? -✓✓ Flattest curve on the front. Old way of
doing it do to cosmetics
• What is Vogels formula used for? -✓✓ Creating best form and n standard
surfacing
• Vogel's Formula (+ lenses) -✓✓ Spherical equivalent + 6.00
• Vogel's Formula (- lenses) -✓✓ Spherical equivalent + 6.
• Corrected Curve Theory rules: -✓✓ #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? -✓✓ Nominal - general category (ex.
4.25 or 6.00)
Actual/True curve- real measured curve/sag depth
,• Index of refracting formula -✓✓ Speed of light in air/speed of light in material
• Speed of light in air? -✓✓ 186,000 miles per second
• Flint glass index of refraction and abbe value -✓✓ 1.58-1.69 & 30-40
• Barium glass index of refraction and abbe value -✓✓ 1.51-1.616 & 55-59
• Highlite glass index of refraction and abbe value -✓✓ 1.70 & 32
• CR39 index of refraction and abbe value -✓✓ 1.49 & 58
• Poly index of refraction and abbe value -✓✓ 1.59 & 30-32
• Trivex index of refraction and abbe value -✓✓ 1.53 & 43-45
• 5 categories of absorptive lenses -✓✓ 1- tinted solid glass
2- glass w/surface coatings
3- tinted plastic
4- photochromic
5- polarized
• Absorption definition -✓✓ Reduction of transmission of radiant energy through a
medium
, • Transmission definitions -✓✓ Transit or passing if radiant energy through a
medium
• Grey tint characteristics -✓✓ Most popular
Least amount of color change
• Brown tint characteristics -✓✓ Uses yellow to increase contrast
Good for hazy days
• Yellow tint characteristics -✓✓ Can be added to any color to increase contrast
Filters out blue light
• Green tint characteristics -✓✓ Good color balance w/better contrast than grey
Transmission curve closes to the human eye
• Pink/rose tint characteristics -✓✓ Reduces glare and softens bright light
situations
• Blue tint characteristics -✓✓ Causes glare by promoting blue spectrum
• Vaccum coatings used for: -✓✓ Mirrors and depositing uniform color on glass
lenses
• Term for snow blindness -✓✓ Photokeratitis
