BIFOCAL CONTACT LENSES

SEGMENT DESIGNS

     Advantages of segment lenses:

         -good distance and near vision
         -can get high add powers

                
    Disadvantages of segment lenses:

        -patient does not have good near vision in upgaze
        -thick lens due to the prism-can cause comfort 
             and edema problems
        -fairly complicated lens to fit
        -patient must have the correct ocular anatomy
        -only available in RGP designs 
            (hydrogel lenses do not translate enough)
        -expensive