Most people don't think twice about glasses. We walk into some eye place, you get a prescription and go pick out new frames. However, there are a ton of different options out there. A couple of these have been significant enough for me to warrant trying to share.
If you are getting new lenses, I highly recommend you ask for free-form digital lenses. This isn't the same thing as a digital lens--the free-form piece is key.
These are the clearest and best pair of glasses that I have ever owned.
Traditional Lenses
Traditional lenses are surfaced by polishing and you end up with a single point in the center of the lens (where your pupil is) that ends up matching your prescription. As you move away from this point, the prescription gets farther away from where it is supposed to be.
If you don't want to read all of this, ask for the Shamir Autograph III (free-form digital lens) in Trivex, but make sure the optical lab won't give you back a lens with 'invisible markings' on the part of the lens that will end up in your frames. (Lenses without markings are an option for single vision lenses)
Free-form Digital Lenses
With a free-form digital lens, your prescription is re-calculated across the entire surface of the lens. This means you're able to use much more of the lens to look through without distortion. For me, it was a night and day difference and I have no plans of ever going back to traditionally surfaced lenses again.
The Shamir Autograph III lens is what I currently have experience with and it is fantastic. However, it has taken a bit of digging/learning to get to where I am now.
Finding a place that is familiar with free-form digital lenses might be a challenge, especially if you are trying to find one that has the smarts and is in your insurance network. It's worth the hunt.
Will this work for you?
If your prescription is between -14.00 to +7.50 with a cylinder to -6.50, you can get the single vision lenses in Trivex. If it's outside of this range, you'll have to ask/do your own research--the ranges are different for the various lens materials out there.
My Adventure
These lenses ship from the factory without digital etchings/markings. However, are later added by the optical lab during their processing. They are supposed to indicate that it was a free-form lens, made of Trivex, in single vision (more on this later) and has the company logo on it. You don't want them.
An optical lab will surface the lens (making it match your prescription) and then mail the lens blank (~3" round piece of lens) back to your eye care place. The local optical place will cut the lens to fit in your frame.
Why these guys would decide to take a precision optical instrument and deface it with this garbage is beyond me. I asked around and their goal was apparently to "make sure consumers can verify they got what they paid for." Which I suppose is great if you are buying your lenses from some shady place. However, it's pretty terrible to look through. When you are wearing the glasses, the 'invisible markings' look like smudges/fingerprints that you can't get rid of. If you take off the glasses and tilt them at just the right angle, you can see that these smudges are actually symbols/text that do indeed indicate the details of the lens.
You can't see these unless you are looking for them. When you are wearing the glasses, they just look like smudges if you try to look through them.
Most optical labs are figuring out that customers hate this and have no interest in trying to look through a company logo on their glasses. As a result, after multiple customer complaints, labs started leaving the etching option off by default.
Make sure you ask if the optical lab can do this, otherwise, you might get back a pair of glasses with smudges (digital etchings) in them that you're going to hate. This must be done at the lab, the local eye care place cannot simply edge the lens differently--especially if you have astigmatism correction.
I've been told that the markings are required for progressive lenses, but optional for single vision lenses
Lens Materials
There are a bunch of these out there. If you have a mild prescription, you probably have polycarbonate lenses. If you have a slightly worse prescription, you probably have high index lenses. Each of these materials has different indexes of refraction (a number that describes how light propagates through it), impact resistance (how hard of a hit it can take before breaking/shattering/denting), abbe value (optical clarity of the material--scale maxes out at 100, your eye is somewhere between 45-50) and a bunch of other values that I'm going to ignore.
You've probably seen/heard of the following materials at some point: polycarbonate, glass, cr-39 plastic, mid/high index plastic, Trivex and maybe others. I'm just going to share information on a couple.
Polycarbonate -- Lightweight, fairly inexpensive, good impact-resistance, abbe value of 30.
Trivex -- Lightweight, slightly more expensive than polycarbonate (less than $40 more), impact-resistance comparable to that of polycarbonate. Abbe value of 43. Is lighter, but slightly thicker than polycarbonate. For me, this equated to the lense being 0.2mm thicker than polycarbonate, which I didn't really care about.
High Index Plastic -- More expensive than Trivex (less than $150 more), impact-resistance much lower than polycarbonate/Trivex. Abbe value between 32-36. Might be a requirement to ensure you aren't rocking coke bottle lenses, depending on your prescription.
Lens Types
There are a bunch of these, but I'm just going to focus on these two as these are your only option in a free-form digital lens at the moment:
- Single vision (nothing special, standard prescription)
- Progressive (prescription gradually changes across the surface of the lens--can give you distance in the middle and up close if you look through the bottom part of the lens)
Lens Manufacturers
There are a ton of these as well. They will take the various lens materials that are out there and make their own version of them. Most have sales slicks that indicate that they do something special/unique.
Optical Lab
After you've picked out a pair of frames, your local store will likely place an order to an external lab. The lab will be responsible for obtaining the lens blank, surfacing it (making it match your prescription) and then shipping it back to your local store. Most of the larger eye care places have a edging machine in the store that will take the surfaced lens and cut it to fit in your frames.
What if I'm lazy and don't want to research this on my own and I do not care about having my insurance cover it?
Visit adseyeware and place your order. You can mail your frames in after you've placed the order, and they'll take care of the rest. It will probably cost you about $200 if you have your own frames and want Trivex. I have no affiliation with them, they just happened to be the place that did mine and will not send you back lenses with etchings on them.
You will need to know what your current prescription is as well as your PD. The PD is the distance between your pupils. If you have had glasses made in the past, you might be able to call the place that made them for you and ask for it. Some places are silly about giving it to you, so you might need to walk into a eye care place and ask them to measure it for you.
ADS Eyeware also spent the time to help me figure out the difference between the awesome lenses I received from them and the non-free-form lenses I had made at a local place.
Frame Information
- Frames all have measurements/sizes on them: bridge width, lens width and the length of the arms. These numbers are usually on the back of the bridge or on the inside of the arms.
- Frame manufacturers will sometimes make the same frames in different sizes--a size that fits your face may exist, but might not be in your local store
- If you already have frames that fit you well, you can use these numbers as a reference.