Digital lenses, also known as freeform or HD lenses, are a relatively new type of lenses which entered the market around five years ago. Many have hailed them as a great step forward in optical technology, but they still have a lot to prove. In order to understand the potential benefits and advantages of digital lenses, we must first understand how traditional lenses are made.
For many years, traditional lenses were created through a labor-intensive process which involved multiple steps as well as pieces of equipment. The process begins with semi-finished blanks which are created for many different kinds of prescriptions. Once a lab receives a patient’s prescription, a proper blank must be selected in order to be cut into the general shape of the prescription. Then, another worker will polish and fine tune the prescription, smoothing out the rough cuts. Finally, the lenses undergo a finishing and quality control process.
As you can see, the traditional manner of making lenses involves many steps and is quite labor intensive. Digitally surfaced lenses streamline this process by compressing all the above-mentioned steps roughly into one. This is possible because of digitally controlled cutting and polishing machines which precisely and consistently follow the designs as well as the specifications put in by lab technicians.
The Benefits 🙂
Besides ease of manufacture, what advantages do digital lenses provide?The truth is, the answer is not so simple. Different types of prescription will benefit differently from HD lenses. However, the two main kinds most people are worried about are single vision and progressive prescriptions. For larger or wrap-around frames, free-form lenses are advantageous because they help prevent the “fishbowl” effect. This means the blurry areas on the edge of your lenses will go away, leaving only more clear space to look through. Not only will you have a greater field of vision, but it will reduce the strain on your eyes was well.The greatest advantage that HD lenses can offer is through higher quality and smoother progressive lenses. By design, progressive lenses are like bi or trifocals without the visible line. This means that there are multiple areas (usually two to three) with differing levels of power. In terms of distance it goes from top to bottom: distance, intermediate, and near sighted at the bottom.
Originally, progressive lenses were made from heated glass molds which were formed over ceramic pucks. This necessarily tied the quality of the mold to the quality of the design of the lens. With digital surfacing, manufacturers can skip this molding step which allows for a greater degree of dependability. It means that a good design will yield a high-quality progressive lens with smoother transitions from top to bottom and greater visual resolution.
If you’re interested in getting digital lenses for yourself, then check us out at Lensabl. By default, our progressive lenses are digitally sculpted and have an exclusive in-house design by Shamir. However, we do offer other designs by Shamir and Verilux which are available by request. Additionally, our single vision lenses are designed by Essilor, but they are not HD. Digital single vision lenses by Shamir are also available upon request.