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OCPP 102 2.3 (Presbyopia - Multifocals - Progressive Lenses): Questions & Answers
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OCPP 102 2.3 (Presbyopia - Multifocals - Progressive Lenses): Questions & Answers
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OCPP 102 2.3 (Presbyopia - Multifocals - ProgressiveLenses): Questions & Answers
Accommodation Right Ans - Variable focusing ability provided by the
crystalline lens and related intraocular muscles.
At rest, flexes Right Ans - When the eye focuses on distant objects, the lens
is ______. But when summoned to focus upon an object at less than 20 feet, the
crystalline lens ______ to provide additional plus power.
Plus power Right Ans - In order to accommodate, the lens has to supply
additional what?
15 diopters Right Ans - At birth the lens is very flexible and has about how
much accommodation?
5 centimeters ( about 2 inches) Right Ans - If all is diopters of
accommodation from birth are used, the eye would focus where?
Lens capsule Right Ans - capsule (bag) that encloses the crystalline lens
More dense Right Ans - Because of the lens capsule, multiplying cells aren't
washed away. This causes the lens to become ________.
Near point Right Ans - the closest distance at which an eye can focus
84% Right Ans - What percent of the US population over age 55 needs
eyeglasses?
Benjamin Franklin Right Ans - Credited with the concept of correcting
presbyopia with bifocal lenses.
August Morck Right Ans - Invented cement bifocals, patented in 1888
Cemented Kryptok Bifocal Right Ans - Bifocal invented by John Borsch in
1899. Patented technique of using high index flint glass bifocal segment
cemented into a ground countersink curve on the carrier lens with Canada
balsam cement.
, Kryptok bifocal Right Ans - Developed in 1908 by John Borsch, improved
bifocal type that used a high index flint glass segment and a countersink curve
in the distance carrier, which are fused together instead of cemented.
Chromatic abberation Right Ans - Disadvantage of using Kryptok bifocal
lenses:
Nathan Stanley Right Ans - Patented the D style segment bifocals that is
popular today in the US.
Fused glass Right Ans - Until plastic became a popular lens choice in the
1970's, what was used for the standard bifocal construction type?
John Isaac Hawkins Right Ans - Credited with the invention of the trifocal
in 1826.
Virgil Hancock Right Ans - Awarded patent for rounded top trifocal design
in 1932.
Virgil Hancock Right Ans - Developed first fused straight-top trifocal in
1936.
Image jump Right Ans - The sudden displacement of an image as the bifocal
line is crossed by the eye
The technology to make them was not available Right Ans - Why did it take
so long for progressive addition lenses to be created?
Radius of curvature Right Ans - In order to increase plus power through
out a PAL, the __________ must become continually shorter.
Steeper, plus power Right Ans - In PALs, shortening the radii produce an
increasingly _______ surface, which provides the progressive ________.
Distance, intermediate, near Right Ans - 3 zones of a PAL
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