ABO Q&A Simple to understand with complete
solutions
How many millimeters are in an inch? -ANSW- 25.4 mm = 1 in.
List the colors of the spectrum, from longest wavelength to shortest. -ANSW-
(ROYGBIV) Red, Orange, Yellow, Green, Blue, Indigo, Violet
How are the bands in the UV spectrum categorized? -ANSW- A, B, & C (with C being
blocked by the Earth's atmosphere)
What is the speed of light? -ANSW- 186,000 mps
Define "Index of Refraction" -ANSW- the degree that light is bent in a given material
based on that material's denisty
How is the speed of light determined? -ANSW- speed of light/speed through material
What is the index of refraction for polycarbonate? -ANSW- 1.589
What is the index of refraction for CR39? -ANSW- 1.49
Is material more or less dense with a higher index of refraction? -ANSW- More
What is the index of refraction of glass? -ANSW- 1.523
What is the standard index of refraction in the optical industry, which all instruments are
calibrated to? -ANSW- 1.523
Define Dispersion -ANSW- when light is broken down into basic colors causing a
rainbow effect
What is abbe value (or Nu value)? -ANSW- measure of how easily dispersion happens
abbe values are between what numbers? -ANSW- 29 and 60
Do higher or lower abbe values result in the least dispersion and best vision? -ANSW-
Higher!
what is the abbe value for plastic? -ANSW- 59-60
, what is the abbe value for glass? -ANSW- 60
what is the abbe value for high index resin? -ANSW- 43
What is the abbe value of polycarbonate? -ANSW- 29-31
what 3 things happen as light hits a medium? -ANSW- Refraction, Absorption,
Reflection
More curce induces (more or less?) refraction -ANSW- more
What is a diopter? -ANSW- the measure of power of a lens to refract light?
A lens that can focus parallel light to a point at one meter has what power? -ANSW- 1
diopter
What is the formula for determining diopter power? D = ? -ANSW- D = 1/f whee f is the
focal length of the lens in meters
How do you determine focal length, given the power of a lens in diopters? -ANSW- f =
1/D
How do you convert magnification to diopter power? -ANSW- muiltiply the
magnification by 4(2x is 8 diopters)
What are the 3 types of plus lens configurations? -ANSW- Bi-Convex ()
plano convex [)
meniscus ))
What type of lens magnifies an image? -ANSW- plus lens
What type of lens is thicker in the center and thinner at the edges? -ANSW- plus lens
What type of lens demonstrates "against" motion (if the lensi smoved side t side, the
image seems to go the opposite direction)? -ANSW- plus lens
What are the three types of refractive errors that plus lenses correct for? -ANSW-
Hyperopia, presbyopia, aphakia
What are 3 types of minus lens configurations? -ANSW- bi-concave )(
plano concave )]
meniscus ))
What type of lens minimizes an image? -ANSW- minus
solutions
How many millimeters are in an inch? -ANSW- 25.4 mm = 1 in.
List the colors of the spectrum, from longest wavelength to shortest. -ANSW-
(ROYGBIV) Red, Orange, Yellow, Green, Blue, Indigo, Violet
How are the bands in the UV spectrum categorized? -ANSW- A, B, & C (with C being
blocked by the Earth's atmosphere)
What is the speed of light? -ANSW- 186,000 mps
Define "Index of Refraction" -ANSW- the degree that light is bent in a given material
based on that material's denisty
How is the speed of light determined? -ANSW- speed of light/speed through material
What is the index of refraction for polycarbonate? -ANSW- 1.589
What is the index of refraction for CR39? -ANSW- 1.49
Is material more or less dense with a higher index of refraction? -ANSW- More
What is the index of refraction of glass? -ANSW- 1.523
What is the standard index of refraction in the optical industry, which all instruments are
calibrated to? -ANSW- 1.523
Define Dispersion -ANSW- when light is broken down into basic colors causing a
rainbow effect
What is abbe value (or Nu value)? -ANSW- measure of how easily dispersion happens
abbe values are between what numbers? -ANSW- 29 and 60
Do higher or lower abbe values result in the least dispersion and best vision? -ANSW-
Higher!
what is the abbe value for plastic? -ANSW- 59-60
, what is the abbe value for glass? -ANSW- 60
what is the abbe value for high index resin? -ANSW- 43
What is the abbe value of polycarbonate? -ANSW- 29-31
what 3 things happen as light hits a medium? -ANSW- Refraction, Absorption,
Reflection
More curce induces (more or less?) refraction -ANSW- more
What is a diopter? -ANSW- the measure of power of a lens to refract light?
A lens that can focus parallel light to a point at one meter has what power? -ANSW- 1
diopter
What is the formula for determining diopter power? D = ? -ANSW- D = 1/f whee f is the
focal length of the lens in meters
How do you determine focal length, given the power of a lens in diopters? -ANSW- f =
1/D
How do you convert magnification to diopter power? -ANSW- muiltiply the
magnification by 4(2x is 8 diopters)
What are the 3 types of plus lens configurations? -ANSW- Bi-Convex ()
plano convex [)
meniscus ))
What type of lens magnifies an image? -ANSW- plus lens
What type of lens is thicker in the center and thinner at the edges? -ANSW- plus lens
What type of lens demonstrates "against" motion (if the lensi smoved side t side, the
image seems to go the opposite direction)? -ANSW- plus lens
What are the three types of refractive errors that plus lenses correct for? -ANSW-
Hyperopia, presbyopia, aphakia
What are 3 types of minus lens configurations? -ANSW- bi-concave )(
plano concave )]
meniscus ))
What type of lens minimizes an image? -ANSW- minus
