• Can prism be added to the lenses I have now, which are progressives?


    Question:

    I do not need a new prescription but wondered if prism correction could be added to the original lenses I have now, which are progressives.


    Answer:

    Unfortunately, prism that is "ground in" to glasses is added when the lenses are manufactured. Another type of prism can be added to existing lenses. It uses Fresnel optics in a plastic membrane which adheres to the surface of the lens. These prisms work, but do somewhat blur the image, can get dirty, and have lines that other people can see. These are particularly good for trial fits or when we think the power of the prism may change.