Single Vision vs Freeform Single Vision
When you’re being fit for a pair of single vision glasses, you might be asked, “do you want regular single vision lenses, or freeform single vision lenses?”
What is “freeform”?
Freeform refers to the method used to manufacture lenses. Before the use of freeform technology, “digital conventional” manufacturing methods were widespread. These “conventional” lenses were much simpler, as conventional manufacturing did not allow advanced lenses to be made. Lenses manufactured using freeform techniques can take advantage of modern lens designs, since freeform manufacturing offers much greater control and precision when creating lenses.
What does that mean for my lenses?
A freeform single vision lens design allows the lens to be carefully crafted to expand the clear viewing area toward the edge of the lens. One of the most important advantages that freeform single vision lenses provide is to reduce what’s called “barrel distortion”.
Barrel distortion causes the view through your glasses to be warped
Does this mean I’ll have clear vision everywhere in my single vision lenses?
Potentially, yes! Essentially distortion-free, edge-to-edge clear vision is possible with freeform single vision lenses, while it isn’t with conventional lenses.
Things are not quite that simple in the real world, of course. The higher your distance prescription or astigmatism correction, the more optical complications you’ll have from many different causes, not all of which can be perfectly corrected. Freeform lenses can help people with high prescriptions, but they won’t eliminate all issues. Talk to your optometrist to find out if freeform lenses are a good option for you.
Conventional single vision lenses suffer from various optical issues, which, when combined, lead to the edges of the lenses being excessively blurry and distorted
Freeform single vision lenses compensate for some types of distortion (such as barrel distortion), which increases the size of your real-world viewing area
