The Truth About HD Lenses
My dear faithful patrons of TLG, I'm going to get on a soap box for a minute and talk about a term that has created a huge misconception in the optical world: "HD lenses". If you're reading this, I am sure at one point in the past few years you have either been sold or been marketed the all powerful HD lens. But, let me clear the fog for you here. There is no such thing. There is however a higher tech lens option. There! I said it! My conscious is clear and my rant has begun. Now, you ask, if there is no such thing, then why am I being sold these lenses, and what exactly are they?
Let me begin to sort these questions out by explaining the process of making a prescription lens. Today there are two main processes for creating the light bending effect, or "prescription lenses": standard surfacing and digital surfacing. Standard surfacing is an older process of grinding different curvatures into either the front or back surface of a lens in order to create the right ratio in order to bend the light to fill each prescription need. Labs have a hockey puck-sized sander with a curve that matches each possible prescription that would "grind" the appropriate curve into the the surface of the lens. Afterwards, each lens is polished for a seamless finish. With this process there can be natural aberrations and variation of the prescription throughout the lenses. These become more noticeable in higher prescriptions.
Digital surfacing, however, is a much newer system that has gained enormous popularity over the last decade. In this process a diamond cutting system guided by advanced software will grind the curves into the lenses. The system is so accurate that almost no polishing is required in comparison and variation/aberrations are greatly minimized. Many times patients with a high RX, especially those with minus lenses or astigmatism, will notice that the edges of the lenses are more clear than standard surfacing. This is because the prescription can be cut more accurately throughout the lens as opposed to standard surfacing. I have seen many a face light up when donning these lenses for the first time. Digital surfacing can become even more complicated and more specific by compensating for frame shape, tilt, distance from the eye and sometimes even eye-movement patterns. Both single vision and progressive lenses can be finished this way.
Progressive lenses are now almost all finished digitally: in fact, that's pretty much standard at most private stores and all we sell in progressive lenses.
Now, to be fair, while the majority of people will notice an improvement with digital surfacing, some either won't notice a difference or won't like the compensation. Lower single vision prescriptions tend not to notice (I am in this category: I can't tell for the life of me). This is why, for lower prescriptions, I tend to recommend putting your money toward a nice coating instead. This leads us in to my next point.
Many lenses sold as HD include an anti-reflective coating. Of course, an anti-reflective coating will improve vision, especially under florescent lights, and at night. Much of the marketing for HD lenses includes two photos of what you can expect to see through your lenses with and without HD, and a large percentage of this effect can be gained with a simple, quality coating that keeps light from dispersing on the surface of your lenses. So again, this is not some "magic" new product.
It is this digital surfacing that is being sold as HD lenses, and it's truly a marketing ploy. "Let's take a term previously reserved for television and phone screens and use it to sell more glasses!" Many big box stores are getting customer riled up over their "new tech", but as stated above, many private labs have been using digital surfacing for the past decade—some even longer!
So, can we make you lenses that use the latest tech? Absolutely, YES! Are we going to say they are HD? Definitely not. Here at TLG, we don't want to give you any marketing garbage. We will walk you through what options would be the best for you based upon lifestyle, prescription and budget.