ABO Practical Exam Questions and Answers 100% Verified

When should you use occluder? - For noticeable eye abnormalities. Ex.: Strabismus. Also to check binocular PD by occluding each eye to see if eye moved when occluded. BD/BD - Cancels- subtract BI/BI - Compounds- add BI/BO - Cancels- subtract Binocular PD - Total PD of both eyes together. From one pupil to the other pupil. Black numbers on lensometer power drum - (+) BO/BO - Compounds- add BU/BD - Compounds- add BU/BU - Cancels- subtract Cancelling effect- subtract prism amounts - BU/BU BD/BD BI/BO Cylinder power is always used to determine if axis - Meets ANSI standards Fill in all parts of the reading values found in the correct form, including all: - Zeros Ex. X 090+0.50 Focus sphere lines first, if cylinder lines focus first - Rotate axis drum by 90° How to check for vertical imbalance - 1) mark OD, OC by centering within retical 2) without moving the lens table, move to OS lens 3) if not still centered, there is imbalance. Lensometer is also referred to as - Lensmeter, focimeter, vertometer Major Reference Point: (MRP) - The point on a lens where the patient is provided the prescription as written by the doctor. If prism is not called for in the prescription then the lens OC and the MRP are the same. Measure cylinder value of the lens by: bringing far lines into focus, THEN: - Subtract current measurement on power drum from spherical reading. Monocular PD - Individual PD of each eye. From pupil to bridge. Near reference point (NRP) - represents the location on the surface that provides the full target Add power, which is the optimal location for verifying the Add power of the prescription. It is located at the center of the near checking circle ink marking. Optical Infinity - used to measure distance PD-is a distance of about twenty feet. P=hcmxd - Prentice rule P(prism) Hcm(amount moved) D(diopter)PD for bifocals and trifocals - Binocular PD for Single vision & progressive - Monocular Powers between 0.00 & +/- 3.00 - Read in 1/8 diopters .12 .37 .62 .87 Pupillometer set @ 40cm - Used to measure near PD. About 16 inches Add power is - The difference between the sphere and power in reading area of lens. *subtract full reading amount from sph. value Pupillomters set @ 65cm - Used to measure intermediate PD. About 25.5 inches Red numbers on lensometer power drum - (-) Take binocular PD for - Bifocal Rx- measure for distance and near Critical Rx- which also includes intermediate Take monocular PD for - Progressive lens- distance Single vision- near Single vision- distance Single vision- intermediate