Good method to convert RX for different use

[glasses cheap]

I have a ordinary multifocal Rx for distance and near corerct, but i want to buy a pair of multi-focal glasses fro computer and reading use. Then my doctor tell me a good method to conver Rx for different use. Here i would like to share with your guys:Simply split the Add number in half (if there is no equal division of the Add number, you’ll need to decide if you want your focus closer or further, and the quarter diopter difference will shift the depth of the focal plane, accordingly) and combine half of the Add with the Sph. The balance of the Add will stay in that data entry field.