Free Form or Digitally Surfaced Lenses

What is a free form lens and why is it different than other lenses?
       Free form is a computerized design and manufacturing process.  Unlike conventionally surfaced lenses, which use a wheel embedded with fine diamond particles to roughly grind a prescription into a resin lens blank, followed by a fining and polishing process, the free form process precisely cuts the prescription in the lens blank using a single diamond point guided by the computer software program.  There is no fining or polishing needed in free form manufacturing. The computer program is designed to make a distortion free lens.
       Free form processing enables lenses to be made to a .001 Diopter power accuracy, which is about 25 times more accurate than a conventional lens.  This gives lens designers the ability to attempt to reduce lens abberations even more than in the past.  This is why you'll hear claims of less peripheral distortion and blur.  Also called HD lenses.
       Some of these lenses customize the design by utilizing different measurements of the frame.  If you wear a progressive or "no-line" bifocal, you no longer have to worry about using a larger frame or one that has a large vertical measurement because the free form program chooses the correct design for the frame.
       Another feature found in these lenses is the compensation for things like vertex distance (the distance from your eye to the front surface of the lens), face form (the curvature of the frame) and pantoscopic tilt (the angle of the lens while wearing the glasses).  These factors can be measured by the optician and their contribution to the lens power errors can be compensated.  The result is a lens that is completely customized for the wearer.  Some premium sunglass lines, such as Oakley, Nike, and Maui Jim exclusively use free form lenses.

Flak Jacket by Oakley

Most people will see through a conventional lens just fine, digitally surfacing makes that lens better.  While educating the patient in the office, I'll use the comparison of video technology.  If you're old enough, you remember having a black and white TV.  This worked great until you got your first color television.  This was followed by the flat screen which gave a wider angle to view the TV and now we have the HD TV's which have the widest viewing range and clearest picture.  Every TV you had worked fine, technology made it better.

            For people who had problems in the past with standard progressive lenses because of peripheral abberations or distortions when moving your head, you would be an excellent candidate for a free form progressive lens.  As I mentioned earlier, they a custom designed for maximizing your viewing area and minimizing distortions through the free form program.
       Digital technology will cost you more.  The software to make the lenses is expensive and they will do much more for you.  Remember, most of you rely on your glasses to see almost every waking hour of the day, this is a very good investment, just like that HD TV.  Make sure to add a quality anti reflective coating for the best vision you ever had!