Math For Abo Test Study Guide Graded A+

what is nominal power? {Ans: sum of both the front and back surface powers f1+f2=ftotal}What is slab off? {Ans: AKA: bicentric grinding used to correct vertical imbalance that produces a vertical prismatic effect in the lower half of one lens only starting at the seg line. Used when if there is more than 1.50 D of prism.}Example of image jump: How much jump does a flat-top segment f: seg width =25mm seg depth= 17.5mm add power =+1.50D? {Ans: (flat top is a small round lens with top cut off) 1. Find distance from the seg line to the seg OC, subtract 1/2 of the seg width from the seg depth. Distance= 17.5 -(1/2seg width 12.5)= 5mm 2. Image jump is determined by finding the prismatic effect of the segment at the point on the upper seg line. Distance =5mm Prism= (0.5)(1.50)= 0.75D prism}How do you find spherical equivalent? {Ans: 1. take half the value of the cylinder and 2. add it to the sphere power Sphere + cylinder divided by 2= spherical equivalent}A Box: 53 DBL: 15 ED: 55 PD: 30/32 OD: 68/2 =34 OS: 68/2=34 What is the MBS for the rt and left lens?