ABO / NAO Questions and Answers Already Graded A

ABO / NAO Questions and Answers Already Graded A what is the conversion from inches to meters? one meter equals approximate 40 inches 20 feet is equivalent to how many meters 6 what measuring device is used to accurately measure A and B measurements of a finished lens or pattern box - o -graph what is the lens power in the 90th meridian for this lens prescription? +3.00+1.00x180 +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? 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? tell them to call a dr. 60 degrees from the axis a cylinder will show what percent of its power? 75% if your lensmeter reads -.25 with no lens, a lens that measures -3.00 -1.50 x 180 is actually: -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) 3.00 mm ( exception 2.55 ) the Geneva Lens Measure is calibrated for what glass of index? 1.530 what is the nominal power of a lens? 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? 1 down if the eyewires touch the cheeks, what adjustment would you make to take care of this condition? decrease the pantoscopic tilt frequently, bicentric grinding is used as a means of obtaining prism in the reading field to correct induced prism imbalance. the usual correction during the fabrication process is achieved by grinding prism in which direction? up - the net effect of bicentric grinding is the addition of base up prism to the lens from the seg downward when a frame is said to have retroscopic tilt what condition is meant? the bottoms of the eyewires are out further than the top bicentric gringing is synonymous with what? slab off the correct term used to express the amount of prism in a lens is what? prism diopter what is the definition of refraction? the bending of a ray of light when is goes from one medium to another what is the power cross? a schematic representation of the two major meridians of a lens or lens surface how high should the seg height for an rx of +12.50 OU be? as high as the patient can tolerate to reduce oblique astigmatism as the wearer looks down through the lens