ABO Practical Correct Questions & Answers(RATED A+)

Single Vision - ANSWER corrects for one distance Multifocal - ANSWER Corrects with two or more prescriptions (or 'powers') Bifocal - ANSWER lens having two focus strengths Trifocal - ANSWER pertaining to having three focus strengths Calculating Prismatic Effects - ANSWER obtained at the center of an optical lens by producing a difference in edge thickness, either by grinding the back surface at an angle to the front surface during lens surfacing or, if the lens has sufficient power, de-centering the optical center of the lens Compounding Prism - ANSWER BI & BI BO & BO BU & BD Cancelling Prism - ANSWER BI & BO BD & BD BU & BU Prentice's Rule - ANSWER P=hcm x D P=amount of prism created h= number of cm OC moved cm= centimeters (convert to mm, divide by 10) D= power in meridian with error Vertical Imbalance - ANSWER The difference in vertical prism power at the reading level in a pair of lenses. OC Height's by lens - ANSWER SV = 1/2 of