Now we have three differnces lenses.
    1, Progressive multifocal lenses
    2, Photochromic lenses
    3, progressive multifocal +photochromic lenses
   
    What is Progressive multifocal lenses?
    Progressive multifocal lenses (also called progressives, progressive addition lenses, and PALs) are true "multi-focal" lenses. Instead of having just two or three powers, progressives gradually change in power from the top to the bottom of the lens, offering a large number of powers for clear vision at all distances - distance, intermediate, near and everywhere in between.
                           
     In addition, progressive multifocal lenses provide a more natural correction of presbyopia than bifocal or trifocal prescription eyeglasses.
     With progressive lenses, you can look up to see clearly across the room and in the distance. You also can look ahead to view your computer in the intermediate zone and drop your gaze downward to read and do fine work comfortably through the near zone of the lenses.
                          

    Why progressive lenses? 
    You may be maturing, but "mature" doesn't have to mean "old." If you are in your 40s (or older) and are having trouble reading fine print with your glasses, progressive lenses offer a younger-looking appearance and other advantages over the lined bifocal lenses your parents wore.

    So, for progressive multifocal lenses, we provide 1.56 mid-index multifocal lens and 1.61 high-index multifocal lens.
       for $21.90 a pair

    AND

      for $24.90 a pair
  
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     What is Photochromic lenses?
     Photochromic lenses are eyeglass lenses that are clear (or nearly clear) indoors and darken automatically when exposed to sunlight. Other terms sometimes used for photochromic lenses include "light-adaptive lenses" and "variable tint lenses."

The molecules responsible for causing photochromic lenses to darken are activated by the sun's ultraviolet radiation. Because UV rays penetrate clouds, photochromic lenses will darken on overcast days as well as sunny days.

     
     
    Available now in Silver Shadow, Dark Brown
    

    AND 

    

    1.61 high-index photochromic lens, only $23.90 a pair ;
    1.67 high-index photochromic lens, only $39.90 a pair.