Glasses.com (1-800-Glasses) is run by the same people as 1-800-Contacts. This is pretty much a household name in contact lenses, so I felt fairly confident wading into online glasses buying with this company. Before I begin, I want to just make it clear that Glasses.com is not compensating me in any way for writing this review. I have noticed that most other reviews around the web are "sponsored", and they are pretty useless because of it. A sponsored review is like a sponsored politician!
Policies, guarantees and warranties
Glasses.com has some of the most generous policies for customer satisfaction in online marketplace. They offer a price-match guarantee, so if you see your glasses cheaper on another website, you can save even more off their already reasonable prices. (Note that the price match only applies to a frames+lenses package. More on this later). They have a one-year manufacturer's warranty against defects on the frames and lenses (full replacement value) and even a one-year anti-breakage policy. If you manage to sit on your own glasses, for instance, they'll cover 50% of your cost to replace them. Talk about idiot-proof. Then there is the no-hassle, 30-day money back guarantee. Even though their prices generally work out a bit higher than the other retailers in this review (I could have gone cheaper by choosing a cheaper frame), there really is no risk because you're assured all your money back if you're not happy. Finally, as described in Part 1, they offer free in-home try-on (IHTO) so you can test out your favorite frames before you buy them.
These policies put them well ahead of, say, ZenniOptical, who charge you for returns and don't offer IHTO. In my case, I would have to be really lucky to find the right frames sight unseen. So, while $6 glasses might seem appealing, it could cost nearer to $100 after you add in high-index lenses. That's a lot of money to risk without a full refund if something goes wrong.
Some of the other features of the Glasses.com shopping experience worth mentioning are that the customer service is fast and friendly. They have live chat on their website, which I actually prefer to telephone. There always seems to be someone around to answer my questions at the odd hours that I happen to be at my computer (usually 1:00am). I have to admit that for the purposes of this review, I contacted them via live chat about lots of stuff, even miniscule things. They were always courteous. At one point, I called their help line to ask about a defect in one of the trial frames that they had sent in the first box so I could try a new pair in the second box. Again the service was great, and I even got a spontaneous follow-up call within minutes of when the second FedEx delivery arrived. The cheerful and prompt service, however, did not stop me from having some sizable hiccups down the line, which I will address below.
Glasses.com also offers virtual try-on, where you can upload a photo of yourself to "try on" frames via the web. Of course, it's not perfect, but you can at least see when you're going to look especially goofy. In addition to virtual try-on, there's a 360 degree view of all frames and the dimensions of each frame are also given; that is, stem length, lens width, bridge width and – equally important – lens height. If you already have glasses that you like, you can use these measurements to judge how much bigger or smaller the new frames will be. This was handy, because once I had an ideal size in numbers, I could expand my search beyond the frames which would initially look like obvious choices.
My shopping experience at Glasses.com
1. Frame Selection and IHTO
The site differs from the other two under review here (Warby Parker and DBVision.com) because Glasses.com carries name brand designer frames like Oakley, Eddie Bauer, Lucky and Guess. I actually only found the site because I was googling for a pair of designer frames that I had tried on in person at a local optician. Glasses.com beat the price by $70 (or 40% off), which is no small savings.
For my first in-home try-on (IHTO), I ordered the frames that I had previously tried on in uncomfortable settings in my local money-grubbing opticians, plus 4 others. They arrived in a neat black display box a mere 2 days later. The speed of shipping from Glasses.com has been consistently fast.
I'm not vain or brave enough to show everyone my blind deer-in-headlights stare behind trial frames. Suffice to say that when my 7-day trial began, I tried to make the best of it by trying them all on several times, taking photos of myself to review later (I can't see myself in a mirror without my prescription lenses on), and showing family members for their advice. I was really only aiming at the one pair I had tried before, but the other choices I selected online to fill my box threw me for a loop and made me even more indecisive. Luckily, the freedom of trying at home was great. There was no pressure at all. I ended up ordering another set of trials just to be sure before buying. Glasses.com lets you mark your IHTO as returned after you drop them in your mailbox with the prepaid shipping label. Then you're free to order another set.
After a series of in-home try-ons spaced over a couple of weeks, I ended up choosing my original favorites that I had first seen offline, which goes back to my recommendation to shop online and offline simultaneously in order to find what you like. They have metal fronts with acetate sides. I love the full plastic/acetate frames they carry at WP and DBvision, too, but I'm partial to adjustable nose pads on my primary pair. Also, a lot of the plastic frames I've tried (notably Ray-Bans) have been much heavier than metal ones and with noses a bit too wide for me. Once I add in high-index lenses, if the fit is not right on the nose, it can't really be adjusted and will just keep sliding down.
2. Prices and Ordering
I mentioned that Glasses.com had the frames I wanted at $70 off retail. This was a great savings, but their lens prices are higher than some of their online competitors. You must choose one of their lens packages to complete your order.
The thinnest lens they offer is 1.67 high-index, and their premium anti-scratch version is $129. My total with frame and the upgraded lens came out to $250. I did vacillate a bit before deciding to place the order. At first the price put me off and I thought about just getting the frame online and having the lenses filled by my optician. Even though my optician was going to charge me $375 just for the lenses, they would be thinner, "digital lenses" which supposed allow for a better range of vision. Unfortunately, on Glasses.com you have to buy the frames and lenses as a packaged deal. (The frames alone were cheaper on another website, anyway.) So I went back and forth a bit and then decided to take the risk and buy from Glasses.com, since I could return them risk free if they were not right.
First Order – July 26, 2012
As it happens, I received a promotional code that I could apply to my order. With that final price reduction, I was even happier to order them and see what I got. I finally placed my order on 7/21 and tried not to get my hopes up. The order went through on a Saturday and they arrived the following Thursday (7/26).
My first thought was, wow, that was fast! Then the speed made me a little nervous. Can they really do it so quickly and not sacrifice quality? I opened the package, hoping that my long wait for some new specs was finally over. Thus far I had done about 6 IHTOs, but I had yet to purchase any with my prescription in them. The box opened easily to reveal my order receipt, a new black case with the glasses inside, and a microfiber pouch. There was no packing material keeping the case secure. It was just rolling around in there. That worried me since it had been in transit, but once I gently opened the case, I found the glasses were wrapped in a protective styrofoam sheet that seemed to do the job. Unfortunately, the designer case's inner lining came unglued almost as soon as I opened it. My initial response was bittersweet. They looked in great shape, but I obviously needed to inspect them closer. I'm certainly a retailer's worst nightmare when it comes to checking quality and workmanship.
I had chosen a frame larger and, IMO, more modern than my old pair. I was worried that the lenses at 1.67 would be much thicker than my current 1.70s. So I was happy to see that the frame I had chosen hid the thickness quite well. There was more lens refraction than in my old pair, but that comes with the high-index territory. The alternative is to order 1.74s online somewhere else; choose a different, smaller frame (ugh, I am so done with trying on frames); or pay $500 at my optician. I don't really trust any of the online companies that have 1.74s because they have crappy reviews, don't have the frame I want, don't allow frame trials, or have a bad returns policy, etc.
Having decided that I love my new frames, my happiness at receiving my new glasses so quickly was short-lived for two reasons:
- The lens in the right eye had been cut poorly at the base. That's the only way I can describe it. There was some kind of mark and it looks like a jagged nick in the edge where it sits in the frame. I couldn't get a good photo of it, but I could see it immediately from the outside when I looked in the mirror. It was definitely a manufacturing defect.
- The edges of the lenses were polished to a reflective shine. I don't know who ever thought that this would be a good idea for high-index lens wearers. Supposedly some people think it minimizes the appearance of thickness. I have news for those people. Glossy edges on thick lenses are like putting a girdle on an elephant: not fooling anyone. But seriously, apart from the aesthetics, the glare is hideous for the wearer when looking out of the lens. The shards of light that pierce your eyes are literally painful. I had this experience once before and I absolutely hated it. I would not recommend that anyone with high-index lenses get polished edges, unless the thickness/opacity of the frame blocks the edge light entirely. This is pretty much a deal-breaker for me. Note that the gloss is added to the lens after it is cut, so this process can be omitted.
So I called Glasses.com as soon as I determined the problems to ask them about an exchange because of the damaged lens and to see if the lens polish could be left off my new pair. I was reluctant to simply return them and get my money back because I liked the frames so much.
With my first order, I had less success on the phone than I did with online chat (or so I thought, see below), because every time I called the help line, the entire glasses team was always in a meeting. I explained my problem in fine detail to the very friendly guy who answers the phone only to find out that he actually knows very little about anything to do with glasses or orders or returns or exchanges and he has to get someone to call me back. On this occasion, no one ever did call me back. I ended up on live chat explaining the problem all over again. Not to worry, I was given a return authorization and told that my replacement pair would be sent out expedited at no extra charge. I am not sure how much faster they could arrive than the 4 working days of the previous pair, but that's fine. I also put in a special request to have the lenses left unpolished.
My re-order confirmation came by email confirming no charge and expedited shipping. I waited for my new glasses and crossed my fingers.
Replacement Order #1 – August 1, 2012
I opened them anyway, mainly to see if the lenses were cut better this time and if the edges were still polished. The answer to these two questions was also disappointing. Well, the lenses were cut okay, but the left lens was sitting oddly in the frame, sticking out at the back and sunken in at the front. [Update: I brought them to an optician who pointed out that the reason the lens is sticking out is that the frames are bent!] And of course the edges of the lenses were still polished despite making the request to a very understanding and courteous online chat representative. Although I love all the contact options Glasses.com offers, I do not like when I am told one thing and receive another.
I called up customer service right away and spoke to a friendly rep who listened to my lengthy set of complaints about the packaging, the lenses and the polish. She apologized (again) and said that they would send me out a new order right away (again). She also informed me that it looked like my request I had made via the online chat about not adding polish to the lens edges never made it to their lab (duh), which, she accepted, was entirely their fault. Yes, yes it was. I mean, really, there's little point in having online chat if it's just for show.
I wasn't offered any kind of compensation other than another replacement pair. I'm not really complaining about that, but it seems like the least they could have done. Anyway, more important to me is finally getting some wearable glasses. I now await the arrival of my third and final order from Glasses.com. If this pair is not perfect, I will simply ask for my money back.
In the end, more important than customer service or fancy websites or frame selection is the quality of the product you receive. Thus far, I have not received a quality product. My new order is scheduled to arrive on Monday (tomorrow) and I will update this post accordingly with the results.
Update 08/05/2012: I received an email today notifying me that I would be charged $600 because my IHTO had not been returned. Obviously, this was an error. I sent back the package on 7/18/2012 and proceeded to order glasses from them after that (not something a frame thief would likely do?). I've just been back on to their live chat where the representative informed me that, once again, the mistake is "entirely [glasses.com's] fault":
We have had a glitch in our system recording when we do and don't receive the in home try on boxes back. I have my manager notating your account now so you will definitely not be charged!
I have kept a transcript of the chat just in case the information once again fails to get from the online representative to my account. Glasses.com seems to keep making mistakes when it comes to my glasses.
Replacement Order #2 – August 6, 2012
Quick update: My third pair of glasses from Glasses.com arrived today. The box was in pristine condition, but that's pretty much where the positive comments end. The frames were in terrible condition, the stems stretched out, the metal fronts somewhat bent again, and the lens edges were just as shiny and polished as before. There were even sticky marks on the frames that I had to wipe off. The looked like they had been worn and adjusted before. The prescription felt better than the previous pair, which is also worrying as for quality control. I asked for a call back from a manager so I could discuss my final options for dealing with this. No one called back (again).
In other news, my Warby Parkers also arrived today and they're brilliant. I have to get my eyes dilated tonight so I want to give them a few days before I write a full review.
Update: 4:30 pm. Two and a half hours after I asked for a call within 30 mins, I received a call from Brian at Glasses.com. He has reviewed my account in detail and was very apologetic about all the problems I have had. He was fully understanding about the seriousness of my complaints. He has promised to see a new order through personally from start to finish, including leaving the polish off the lenses and making sure that the frame is in top shape. He also offered me compensation in the form of a full refund of my purchase price, plus a generous $100 credit in my Glasses.com account towards another purchase so I can give them another chance to offer me their ideal customer service experience. I am thankful to Brian for his understanding and, although I am quite exasperated by it all, I look forward to receiving a new pair and finally completing this review.
Replacement Order #3 – 16 August 2012
My third replacement order from Glasses.com was placed over the phone by Brian on August 6th (see above) and arrived on August 16th, via overnight delivery. I had decided that this would be my last and final attempt to have these glasses made (this process had started with several IHTOs over a month ago), so naturally I was a bit nervous upon opening the box. On the phone, Brian reassured me that he would follow the glasses through production to avoid the problems that have plagued my orders. He kept me updated with emails throughout the order process, which took longer than previous orders. In the end, I didn't really mind the extra wait, because I presumed that the time taken would reflect in the final product.
Fresh from the mail delivery, I pulled the zip tab on the box and removed my 4th identical glasses case in as many weeks. I opened it carefully and slowly unwrapped the protective foam sheet from around the glasses. The arms looked straight. The front of the glasses looked even and no longer crooked. This was looking good! Unfortunately, I did find some more sticky gunk on the right stem of the frame. I surmise that this is residue from a sticky UPC label added when the frames come from the manufacturer. I noticed the label on the first pair of demo frames. It was a little annoying to have to find some way to clean it off before I could try them on. I dare not douse acetate with Goo-Gone, so I used warm water and a little lens cleaning solution and gently wiped it clean with a microfiber cloth. That out of the way, I continued my inspection.
My prime complaint with the last pair was that the edges of the lenses were polished to a radiant gleam, one that is very distracting in all light conditions. As I looked at the edges of the new lenses, this looked to be somewhat reduced. Certainly the top edge was less glare-y. The right lens is marginally thicker (because of my Rx), and it looked as if it had been filed at an angle where it stuck out extra. This wasn't so aesthetically pleasing, but it was on the inside of the frame and I couldn't tell when they were on. As long as I could see okay through them, it wouldn't bother me if it cut down on the glare.
Trying them on, I did notice somewhat less "edge glare"; enough that it was not at all bothersome compared to the other 3 pairs. This was a great improvement. I also found that it took my eyes much less time to get used to them and that they were not making me dizzy. Just to be thorough in my report, I did notice increased eye fatigue. I wore them for an entire day and my eyes did get quite tired. I do not experience that at all with my other glasses from Warby Parker, which are immediately comfortable whenever I put them on. But tired eyes on day one was probably to be expected. I was continually "testing" the lenses, giving myself impromptu eye exams, seeing if the sharpest point of vision was directly in front of my pupils, etc.
By the evening of the first day, I was quite excited and pleased that perhaps this time they had finally cracked it and sent me some decent lenses and frames. I went out during the day, spent some time outdoors and went shopping, read books, and used my computer, all with no problems apart from a bit of eye fatigue (no pounding headaches like with an earlier pair). That night, I settled down to watch a movie on TV. I turned off all the lights (as one is wont to do during movie-time). As the film started, I became aware of some strange light glare. My eyes were pretty tired by then, so I rubbed them and the glare seemed to come and go. I also cleaned the lenses with some fresh solution. But the longer I watched, the more noticeable it got.
There were some small vertical glare lines like shards of light that came and went as the scenes changed from light to dark. I guess that can be common with some glasses. I put it down to my eyes being more sensitive after a day of glasses testing. However, what quickly became most worrying and quite unbearable was when I noticed a long, pronounced horizontal "line" in my field of vision. It was like someone held a thin, translucent fishing wire across my face towards the top of the frames; or perhaps more like a faded ray of sunlight shining through trees. At any rate, by this point I was having trouble concentrating on the movie. The Star Trek screen shot (below, right) comes close to illustrating what I mean, although it's intentional in the movie and that wasn't what I was watching!
The next day I started fresh and had a pretty decent day, minus some slight eye fatigue. I began to wonder how long it would take to get used to them and why I was suffering fatigue at all. I persevered and at some point stopped noticing any fatigue. That night, I went to do some shopping and left the store after dark. Driving home, I immediately noticed that horizontal glare line again. Similar to watching the movie, in the dark of night with the street lights, I was plagued by this unbearable line in my field of vision. To be clear, I've been wearing high-index lenses most of my life and I'm used to aberrations like the star-burst pattern you get with traffic lights. This was different. After some Googling, the closest descriptor I could find is a "horizontal lens flare". Apparently, game designers and film makers are quite excited about simulating and enhancing lens flares in their work. It works better in movies than eyewear.
I called Brian on Monday (August 20th) to let him know the verdict: that there is not a great deal of use for a pair of glasses that I can only wear during the day.
He returned my message that afternoon and was as pleasant and understanding as ever. I felt a bit bad delivering the disappointing news, but he took it well. This time, I recommended that he investigate the problem further rather than just sending me infinite replacements. It has already become cost-ineffective for me to keep prolonging this madness, so he must certainly feel the same way. Plus, the continued disappointment and the ridiculously drawn-out process is weighing on me.
I hypothesized that the combined failures of all 4 pairs of glasses fell into two main categories. First was that perhaps the combination of my high-index lenses and the style of frame just would not work together. High-index lenses are aspheric (flatter in front) and a lot of modern frames have a "wrap" style to them. Given the obvious tendency for this particular frame (see Updates 1 and 2) to warp at the front, it might just be an ill-conceived match from the beginning. Second was the Teflon Elite lens coating, which seemingly was the cause of my latest dilemma, when the frame itself was in top shape yet the lens had flares in the dark. Brian promised to check with his lab technicians on these two points and get back to me the same day. If the frame was at fault, he would allow me to choose another one free of charge.
Update: August 21, 2012
He called the next morning (August 21st). I was not optimistic, especially as I had already promised myself that this would be the last time! He informed me that after checking with his lab, they determined that the lens/frame combination was fine and that there appeared to be no defect with the lens coating or the coating process. I commend Brian for doing his best to rectify the situation, but since there was no discernible fault, I wondered how we would proceed. By then I had lost hope and figured nothing could be done. There was little he could offer me that would tempt me to bother with a 5th replacement pair. 5th!
However, Brian's attention to customer satisfaction was clear. It really is difficult to get angry in the face of his sympathetic cheerfulness. After careful discussion with his lab technicians, he offered the solution of providing me with ultra high-index 1.74 lenses (a higher index than is offered by Glasses.com in normal circumstances). These are the thinnest polycarbonate high-index lenses on the market. Although I used to only wear 1.74s, these days they are well out of my price range at most opticians and online retailers.
|Click image to enlarge. [Source: Opticians Handbook]|
Regarding their premium Teflon Elite lens coating (part of their $129 lens package that I opted for), he informed me that a different coating would be applied. I admit that I did not expect an offer for ultra high-index replacement lenses with an entirely different coating. Perhaps I am a glutton for punishment, but I really do like the frames and I would also like to see Brian's endless attempts to make me a happy customer succeed. Since this solution was markedly different from the other replacements, I was willing to give it a try. On top of that, Brian suggested that I just keep the latest pair instead of sending them back again. They're okay for daytime and it's always good to have an emergency spare, so I thought that was reasonable compensation for the trouble.
I really don't want to think about what happens if the new glasses aren't right. I also have $100 in credit to use on the site. There are some nice frames on sale at the moment in their "free lenses" promotion, but I'd have to pair them with the regular 1.67 lens package ($89, reduced in the promotion to $30) to stay within the $100. I'm a little wary at present to put any extra towards them, just in case! I'll just wait and see how it all turns out first.
Replacement Order #4 – Estimated Arrival: 23 August 2012
One month since the date of my first order from Glasses.com, I received my final replacement pair of glasses. I'll try and keep this relatively short given how these updates have stretched out this review. If you persevered and have made it this far, thank you and well done! I hope it has been helpful.
Upon removing the new frames from their case, this pair had obviously been made to the specifications that Brian and I had agreed upon. The polish had finally been left of the edge of the lenses! The edges are matte (like frosted glass), and this in itself reduces nearly all of the edge glare that had been causing some issues. They are much more comfortable to look through. The frames were in great shape. Because the lenses were 1.74 high index (thinner than the first 4 pairs), they fit well into the frame and showed no signs of coming out. Because they don't stick out as much, the lenses sit better aligned against the face, reducing, I believe, some of the aberrations I was experiencing before.
This is pretty significant, because it is possible that potential customers should be advised when their frame choice is not ideal for the lens size given their Rx. This may have been the case with the 1.67s, or may not. I'm not sure, because there were other faults (like the twisted/defective frames). Having said that, the new lenses fit fine and I'm extremely happy with them aesthetically. I am thankful that Glasses.com resolved my issues by offering me the thinner lenses. If I were to order from them again, I can safely say that I would choose a plastic-front frame with their standard lenses, given my prescription and apparent dislike of polished lens edges.
At any rate, the new glasses felt much improved. I wore them for a day and prepared to give them the most important test at night. As described above, the biggest problem with replacement pair #3 was the strange horizontal night glare (lens flare) that was appearing in dark conditions like driving at night under street lights or watching a movie in the dark. I tried not to get my hopes up that the new pair would be any different and waited impatiently for sundown. I tried them for two nights in a row and they were perfect. No glare whatsoever from any angle or in any light conditions. The coating is certainly superior to the Teflon Elite offered on my original order.
While I am certainly pleased that my new glasses are now just right for me, in the context of this review, it is again significant to note that these solutions were made on special order after a month of re-ordering. Naturally, I am still worried that any other glasses I were to order from now would be subject to the same problems. Even though this is a specialist, high index review, I know that these concerns resonate with most glasses wearers who opt for lens coatings to reduce glare and aberrations. I have never actively worried about any of this when buying glasses. I chose lenses and coatings, and they just "worked" as advertised. That is how it should be, so having it done wrong so many times before it was done right was a frustrating experience and one I'd prefer not to endure again.
What I would advise to anyone reading this and wondering if it is worth the risk, is that if you choose to order online - Glasses.com included - make sure you test out your glasses in all conditions. Make use of your full returns period. Don't just put up with things and assume that you'll "get used to it" over several weeks or that you simply "get what you pay for". Remember that the retail value of my Glasses.com pair was $248, which is considerably less than I would find at an optician, but still no small amount. You can always return them and try again (hence the importance of good return policies as detailed in Part 1) or work out a satisfactory replacement with the provider. Glasses.com has been more than accommodating to my needs, even if it did take a bit longer than necessary, IMO. Lastly, be flexible with your frame choice just in case.
I now have a pair of glasses that I am very happy with. I also have a spare set which are admittedly not ideal for night driving, but everyone should have a backup pair.
My last step will be to pop into my local opticians to have my nose pads adjusted. (Glasses.com offers adjustment vouchers to Walmart, but the nearest location is pretty far from here and the Walmarts on Long Island are a much bigger nightmare than loose glasses.) I know YouTube says that you can do it yourself, but because these glasses took so long to get right, I'd rather leave it to a professional. I might also have the hard plastic pads replaced with soft ones. At the moment, they fit a bit loose, which leads me to one last point.
The final thing I would like to address before closing this chapter is that I mentioned dizziness as a perennial problem with my glasses from Glasses.com. For instance, when I first put them on and look down at the ground or left to right, I feel a bit woozy. The new pair has taken a bit less time to adjust, but the feeling is still somewhat there for the first few hours. What's causing this and why does it only happen with my Glasses.com order?
Firstly, it is happening less with this pair than the others. Secondly, I surmise it is likely due to the fact that the lenses (50mm by 29mm) are much taller and a bit wider than I have previously or concurrently worn. This gives me more lens surface to look through and I'm not so used to having to move my head and not just my eyes to avoid normal peripheral distortions. I will discuss lens center-periphery clarity more in Part 4, but suffice to say that the bigger the lens surface, the thicker the edges, and the more peripheral distortion at the thickest parts. So there's that. Third and finally, because the nose needs to be adjusted, they slide down a bit while I'm wearing them. Normally this wouldn't be too problematic, but given the size of the lens, the movement is bound to cause some problems with consistency. After a quick visit to the optician, I expect that they'll be supremely comfortable. Of course, I could be wrong on any of these points, but this is my impression.
It certainly took a while, but Glasses.com came through and provided me with a great pair of specs. As part of the compensation for my troubles, I have some credit to use towards another pair on the site. Of course I worry that their standard lenses and coatings might be ineffective in my case, but I am certainly prepared to give it a try. I have no doubt that with the service I received they will always endeavor to make me a happy customer, and that is extremely important to me.
Continue to Part 3: Warby Parker ...
Also stay tuned for Part 4 of this review where I discuss the unique offerings from newcomer to the online market, DB Vision.
Eyeglasses Review Index
- How to buy glasses online (Part 1): A comparison review
- How to buy glasses online (Part 2): Glasses.com
- How to buy glasses online (Part 3): Warby Parker
- How to buy glasses online (Part 4): DB Vision
- How to buy glasses online (Part 5): Summary and Conclusion
Images (from top): 1-4. screenshots from Glasses.com; 5. photo by author; 6. Stark Trek lens flare from Coffeecommander.net; 7. High-index lens comparison chart from opticianshandbook.com.