Lens Surfacing: The Difference Between Digital and Traditional

Digital lens surfacing is mostly relevant to progressive prescription lenses because the major difference between digital and traditional surfacing is digital’s ability to do custom regions within a lens to suit an individual. Sound a little complicated? It can be.

It’s important to note that, just because a lens is made digitally does not automatically mean it is better than a traditionally surfaced lens. In many cases, there is no difference.

Here’s what sets digital and traditional lens surfacing apart:

• In traditional surfacing, a prescription is polished into a lens using a “tool” that is tailored to a specific prescription. In other words, traditional surfacing labs have pre-made tools stocked for every prescription imaginable.
• For a progressive prescription, a traditional lab must use a semi-finished progressive lens that has the progressive bifocal on one side, then it works the prescription into the side opposite the progressive. This means the size and shape of the bifocal is limited to what’s available in pre-made, semi-finished progressive lenses.
• A digital lab has the ability to surface the progressive bifocal and the rest of the prescription on the same side. The progressive can be altered or tailored to suit an individual’s requirements, and the lab has the freedom to use a semi-finished single vision lens instead of a pre-made progressive.
• The ability to use semi-finished single vision lenses means digital labs have more options for lens colors and sizes. Semi-finished progressives limit the pupil distance and lens size of a prescription; digital surfacing removes this limitation almost entirely.
• If you are comfortable with standard progressives and your pupil distance works in a specific frame, you will be hard-pressed to find a difference between digitally and traditionally surfaced progressive bifocals.
• If you have single vision or use a lined bifocal, there is no difference for you between digitally and traditionally surfaced lenses.
• In a small number of cases, digital surfacing can create stronger prescriptions than traditional in highly curved wraparound frames. For this reason and to increase the options for those with pupil distance conflicts, we are partnered with a digital surfacing lab, allowing us to offer digitally surfaced lenses to our customers for an added fee.

Our lab uses advanced surfacing and edging technology, but we do not do digital surfacing. The major reason is that the vast majority of prescriptions do not need digital surfacing. For the small few who do, we have an outside lab available to accommodate their needs.

One of the biggest misconceptions about digital surfacing is that digitally surfaced lenses are always better than traditionally surfaced lenses. This is simply not the case. Because digital surfacing is so much more complex, it is possible to over complicate a relatively simple prescription, creating poorer vision for the wearer. We bow to digital surfacing for its ability to make better progressives for those with smaller pupil distances, but beyond that there is no difference between the lenses our lab produces and the lenses produced by a digital lab.

If you have more questions or any comments about digital or traditional lens surfacing, please leave us a comment below! We’d love to hear what you have to say. Thanks for reading!