The College of Optometrists

how do you work prisms in varifocal lenses? i was asked this on my cdm's and i did not know. i have tried jalie but i could not find the answer. can anyone help please

Prisms are easy to work with vari's. Varifocals have a thinning prism incorporated into the lens anyway - so a vertical prism is simply a different thinning prism from the other eye. Horizontal prism is worked just like any other lens - its power is measured in the same way - by taking readings from the lens centre. It is possible ot slab off a varifocal if needed - but rarely done. Norvilles offer this I believe. You can also use stick on frsnel prisms. Best to look on the essilor website, I guess for further info. all the best steve

thank you for your help