This Rx is (DV) Distance reading and (NV) Near Sighted.
Looking at the Right (OS) the spherical reading of 4.50 and the cylinder reading of .25 we would calculate with 4.5 plus onehalf of the cylinder .25 equals to 4.63 or rounding down it would be 4.5 diopter.
Now, Looking at the left (OS) spherical reading 2.00 and the cylinder reading of 1.00 we would calculate with 2.00 plus onehalf 1.00 to equal to 2.50 and use 2.5 diopter
The Near Vision reading is a +2.0 in both eyes thus the bifocal or reading lense would be the plus 2.0
