What is the conversion from inches to meters? Right Ans - one meter
equals approximate 40 inches
20 feet is equivalent to how many meters Right Ans - 6
What measuring device is used to accurately measure A and B measurements
of a finished lens or pattern Right Ans - box - o -graph
What is the lens power in the 90th meridian for this lens prescription?
+3.00+1.00x180 Right Ans - +4.00
A lens prescription of -2.25 D is made on a +6.00 base curve. the curve ground
into the ocular surface would be what? Right Ans - the nominal power of a
lens is the sum of its front and back surfaces -8.2
What should you do when a customer complains of severe eye pain? Right
Ans - tell them to call a dr.
60 degrees from the axis a cylinder will show what percent of its power?
Right Ans - 75%
If your lensmeter reads -.25 with no lens, a lens that measures -3.00 -1.50 x
180 is actually: Right Ans - -2.75 -1.50 x 180
According to ANSI Z87.1, the thinnest point in the most plus meridian of
corrective (prescription) lenses used in safety frames should not be less than
what? ( the exception is lenses > +3.00) Right Ans - 3.00 mm ( exception
2.55 )
The Geneva Lens Measure is calibrated for what glass of index? Right Ans -
1.530
What is the nominal power of a lens? Right Ans - the sum of the front
surface and the back surface
What is the seg drop (or raise) for a flat top 28 bifocal needing a seg height of
20mm when the B measurement is 42mm? Right Ans - 1 down
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