Why are blue light glasses a thing

Why blue light filter glasses are important despite Apple's NightShift

To find out more about the function of blue light filters in glasses, Ilseken Roscher and Sebastian Schack from Mac Life met with Mirko Weiss from Yun Berlin for an interview. You can also hear the unabridged interview in the current episode of the Mac-Life podcast "Schleifenquadrat".

Mac Life: “Yun” doesn't sound like a long-established Berlin optician. Where are you from?

Mirco Weiss: Yun is from South Korea. We have been manufacturing eyeglass lenses for the international market for almost 20 years. We prefer to supply our products to other eyewear manufacturers. But retail is the magic word and now we're also going directly to the end consumer. And since Berlin is the “Start-up Captial # 1” worldwide, fortunately the choice fell on Berlin.

ML: Berlin as the only bridgehead to Europe or is there any plans for expansion?

MW: The CEO's daughter is married here in Germany. They lived in Frankfurt, but then decided to move to Berlin and open the shop here three years ago.

ML: For me that also means that I currently only have the chance to order online or actually come here ...

MW: Exactly. We are generally the first in Europe to use this concept, with ready-made glasses in 20 minutes. Berlin is location one. We will continue to expand and the next location will be in South Korea, in Seoul, probably next year. Then we will see that we continue to expand relatively quickly on the European market.

ML: You don't have a location in Seoul yet?

MW: No, this is the first store in the world.

ML: That means, so far you have only done online mail order business.

MW: No, the online mail order business was created parallel to the store. Since we have so many international customers and many still want to reorder something, we launched the online shop a quarter or six months later.

ML: I ask because you said that you have been making glasses for 20 years. So so far you've only produced for others.

MW: Exactly. As a supplier for other eyewear manufacturers.

ML: Already on my first visit I noticed that the store doesn't only work for Berliners. People travel here, probably because of the quality you offer, but also because of the prices. I have also tried to click my glasses together with the values ​​that I have at online retailers and have come across significantly higher prices, so it would have been worthwhile for me to get into the car in Kiel and drive the Buy glasses and drive back. And it would still have been cheaper than buying these glasses in Kiel. How do you come up with the prices?

MW: We actually have glasses tourism. People come to Berlin because of us. Preferably from Switzerland and Scandinavia. In Germany, single-strength glasses cost an average of 440 euros. Which is still a proud sum and mind you is just the average. Of course, there are also thousands of checkout glasses in there. If you make everything yourself, you can call up completely different prices. Then there is the fact that we operate a completely different inventory management system, have a completely different logistics background, are very focused and simply leave out unnecessary nonsense. This ensures that we have leaner costs. That is why we can offer our glasses so cheaply.

ML: Logistics is an exciting point. The fact that you leave the shop with new glasses after 30 minutes, if you have no special requests, is relatively unique. How do you do it?

MW: We plan in advance what glasses are in demand and make sure that we have a good mix so that we have the right glasses for every face as possible. That doesn't always work, but for the most part. The fact that we only have a very limited number of frames makes it difficult to build good models that always fit. But it also has the advantage that we have significantly less inventory management because we don't have 6,000 pairs of glasses in the basement, but only a certain number. So we can massively optimize everything. So we're going for high quantities and that makes the price even more attractive.

ML: We are sitting here in front of a production line that looks completely absurd. What happens to my glasses?

MW: We have 16,000 lenses in stock and will increase that by another 5,000 in December because we are currently doing so well that we actually need them. Of course it has to look great too. Otherwise the customers won't come in. We still have an extremely high proportion of spontaneous buyers. Not only does it look great, it is also a conveyor belt where we put the glasses orders on top. So: the customer decides on glasses, then the glasses are taken off the shelf, are blocked and go to the grinding machine. This means that here in the shop we grind the glasses in 20 minutes, which is nowhere else technically feasible so quickly. We need the conveyor belt to simply free up a bit of space at peak times. An example: if we sell 65 glasses in three hours, then we have 65 of these boxes standing around in the way and the conveyor belt is more or less additional storage space, where the glasses are then processed successively.

ML: For someone who does not work as an optician: 65 glasses in three hours is that a lot? Is that little? Is that a normal Tuesday morning?

MW: The national average is 2.4 glasses sold per day per optician. Then you also know why glasses in traditional optician shops simply cost 500, 800 or 1,000 euros. The 2.4 glasses you have to pay the rent and the employees. That makes things much more expensive. We are completely designed for the masses and so we can call up the super prices.

ML: Will you reveal where your cut is?

MW: At the weekend we go to 100 pairs of glasses a day. That is of course at peak times. But we easily make 1,000 pairs of glasses a month.

ML: What you sold me are not glasses that are just a visual aid, but glasses that also have a blue light filter. Let's start at the very beginning: Why is it good and how does it work?

MW: Well, in general, we don't see with our eyes, but with our brain. The eye is only the sensor to collect the data and transmit it to the brain. The problem is: how is the data relayed without causing an incredible amount of stress in the brain? We have various sensors on the retina that contain a liquid called rhodopsin or visual purple. As soon as a light stimulus falls on these sensors, these rods and cones, this liquid is broken down and the breakdown generates an electrical impulse which is passed on through the optic nerve to the brain. If I have particularly short-wave light - short-wave light is blue light and that is particularly rich in energy - a particularly large amount of this liquid is broken down. This means that the eye is permanently in the “produce, produce, produce” mode, which means that the eye is more quickly overloaded or overtired. This is exactly what happens with monitors, smartphones, computers. Wherever short-wave light comes out, the eye is overwhelmed. The same applies to xenon headlights or cold white LEDs. Cold light has a very high proportion of this short-wave light. For example, if I take a camera and look directly into the flash, everything is black for a short time and then I am blind. In that case all the liquid has been broken down. Then the eye can no longer pass on impulses to the brain and only produce the visual purple again and then I can see again. And so it is with this blue light - of course in a considerably weakened form. But it just ensures that my eye may do more work than it should. That is why we have glasses that ensure that this aggressive blue light component is reduced to a certain extent in order to give the eye a little more relaxation and at the same time to be more efficient on the computer.

ML: Does that mean that the production of this visual purple is also what I perceive as fatigue if this has to happen too often or for too long?

MW: It's hard to say. Everyone feels that differently. But these are definitely the scientific facts about it.

ML: Anyone who follows Mac Life and Apple for longer knows that Apple now has a blue light filter in software in almost all modern devices that they sell. Is that comparable? Or better or worse? Does that maybe even complement each other?

MW: The problem when you work with this “night shift” is that so much blue is filtered out that it is no longer natural vision. This means that the colors are falsified, which is a disaster for graphic designers at the latest.

Of course: if I filter out a lot of blue, then less of this liquid is broken down. But that has the consequence that I can no longer see so intensely.

We have found out through research what the optimum is, so that I can still perceive the colors as naturally as possible and at the same time be as easy on the eye as possible. The result is that we filter out 34 percent of that blue. You can see that the glasses are only very lightly tinted, but that's good enough that designers or graphic artists can also work with them. We also get that as feedback.

ML: That was also what surprised me the most. I have already looked at various of these blue light filter glasses that are also sold in the gaming sector. In terms of tint, they look more like ski goggles, so you can see from a distance that there are yellow lenses in them. I was really pleasantly surprised when you showed me these boho-coated glasses, where you can actually only see this tint in a direct comparison of glass next to glass. Is that advancement in technology? Or is that because you produce more expensive or more elaborate?

MW: I'm not that deep into the matter now. What I can tell you: We basically use mass-colored glass. So it is not the case that any varnish or paint is vaporized or coated on it. But the mass, the basic material of this spectacle lens, ensures that the proportion of blue light is reduced.

ML: Your blue light filter is not an extra layer, but an integral part of the glass? So I don't have to come to repaint at some point?

MW: No, that doesn't happen. This can happen with other coatings, but in that case it is completely irrelevant. But that makes the production more complex and a bit more expensive. That's why the glasses cost 50 euros more.

ML: If this is your own research that brought you to these 34 percent, is that something that is gaining acceptance or do other manufacturers prefer other values?

MW: Yes, that is getting through massively. At first I was very skeptical. So you know scientifically all the advantages and disadvantages, but the extent to which this is accepted by the customers is one of those things. We have had these glasses in our range for about two years now. “Boho” is an Asian word for “wellness”. So they just read “Boho” and buy straight away because they immediately know what's going on. But here, too, it has arrived that if you have a special filter glass, you can simply increase your quality of life a little. And of course that is a great thing in today's world with all the modern media that you can optimize it a bit.

ML: What I found exciting when you showed me the boho glasses for the first time: even if you don't stare into a screen and look outside with the unpolished boho glasses, I noticed that everything looks a bit more contrasting and that's why felt even sharper than with my own eyes.

MW: Yeah. This is because blue, short-wave light has a massive scattering effect that covers many other colors. And if I take a blue filter - or more precisely: a blue damper, because the blue is only reduced and not completely blocked - this scattering and glare effect is reduced and you automatically have a better viewing experience. There are also people with severe ametropia who, from a medical point of view, have serious eye diseases that can barely see. They may need special glasses that filter out 100 percent of the blue. The glasses are bright yellow or orange, but with glasses like this they only have the chance to see anything. This way you can increase your eyesight considerably. In return, the blue is completely gone and the glasses are ugly. But that is basically the next level. Blue is a wonderful color, but too much blue just makes everything a bit caustic.

ML: I would like to come back briefly to software solutions versus hardware solutions. This is also something that I will only experience in the next few days and weeks, but from your experience: do I now have to switch off the blue light filters on my devices or does it even complement each other? Or is that rather confusing?

MW: The blue filter is always on on my cell phone, I never turn it off. If I turn it off now, then I think "Wow, how disgusting-ugly!". In fact, you're just reducing more blue. What I noticed is that I always did a lot with the media in the evenings and I really had a problem getting down and falling asleep. Then you lie awake in bed for an hour. And since I've had Night Shift and these glasses, I've no longer had the problem and now, even if it sounds stupid, I can almost fall asleep again. But that's my experience. How do you want to measure that? It's not like you put your glasses on and the world is changed. That's nonsense. But you can clearly optimize and improve that and I noticed that in myself.

ML: I don't think that's nonsense, nor do I find it stupid, because I feel the same way. I thanked them for that in a conversation with Apple employees. So for Night Shift and especially in connection with True Tone, which adapts the display to the ambient light. Which ensures that I can write or read longer texts in bed even in the evening and get tired of what I didn't have before. So far I've always become more alert.

MW: Sometimes that's because of the text ...

ML: I'm not going to say anything about that. At Mac Life we ​​only have good texts, of course! If I order glasses from you now because I don't live in Berlin. And I don't live in Hamburg or Leipzig, from where I can get here much more quickly, but maybe in Munich or in the Allgäu. Then I'll have you send me the glasses. That means you get my glasses values ​​through a test at the doctor or a prescription and you put the glasses in and send them to me. Now I've made the experience that you put a lot of effort into adjusting my glasses and then I get glasses that are really tailored to the shape of my head. And I learned earlier that even the angle of the lens to my eye affects the effectiveness of the lens. What do I do now when I get the glasses sent to my home? Do I go to an optician then? Do you have certain collaborations there?

MW: No, we are simply too small for that to be able to start any kind of cooperation. Of course, that's the problem with any online shop. When you order something, it's not bespoke. For example, you cannot adjust the temples exactly. You do not know where the viewing height of the glasses is. Then you take standard values. In the vast majority of cases this works perfectly, but of course the main problem is how the glasses fit on the nose. We then set the glasses to their default settings in the hopes that that will work. Nevertheless, the customer is always informed that he has to have it adjusted again somewhere on site. That works in most cases, but I just had another great customer who lives in Lofoten in Norway and the nearest optician is 260 kilometers away and it was a bit more difficult for him.

ML: Then the glasses sit crooked for a while!

MW: The glasses were a bit loose, but he was totally happy that he could look again.

ML: What is your marketing like in Germany?

MW: Oh, our marketing ... I think we now have six people working on marketing. So a lot for Facebook and Instagram, of course. The main focus is on bloggers and influencers. We do a lot there. It is always one of those things: is it really necessary? When you've learned all of this from the bottom up, you think to yourself, "Hmm, there are people who will tell you how to live," but it actually bears massive fruit. That took a while, but we can now clearly see it in the feedback. We've had vloggers here too. Unregistered, they just started filming. We didn't know them either. That was Sami Slimani with girlfriend and two days later the thing had a million clicks.That's a blast and that's our marketing route at the moment.

ML: So you mainly rely on digital channels ...

MW: ... exclusively! No print. Print is absolutely dead. Definitely, especially in big cities like Berlin, this is the last resort. Before I went to another store in Charlottenburg, I thought about which way to go. So I went to print. We made an ad with a 30 euro voucher to cut out. The advertisement was printed a million times in the course of six months. Two people came with the voucher. Then I saw: it's pointless. Posters, none of that makes sense and nobody cares.

ML: Your target group is not necessarily the young, hip, urban Berliner who is out and about in digital media and reads blogs or watches videos on YouTube. You are already talking to everyone, so you have glasses for all ages and yet this way has worked out best for you ...

MW: ... that is the path that has brought us the greatest success at the moment, and with which we are most satisfied. And to come back to the age group. We are very surprised because we also have significantly older customers. They don't necessarily come now because they saw us on some blog. They come on recommendation. And what is always impressive is that even customers well over 70 years old come in and in our shop the customer enters his data into the iPad himself. With this "quick registration" we can use the time for other things. And even for them it is no longer a thing to use the iPad. They get the thing in their hands and fill it in - that works great. So even with the older generation that has arrived.

ML: The old are no longer “the old” either. So the Internet is now almost 25 years old than the World Wide Web, and we've now had real smartphones for eleven years and the iPad is about 10 years old. Of course, this will take hold at some point. I also notice in the readership and in my own circle of families and friends that there is a completely different affinity for technology among “the old” than with those who were “the old” 10 years ago.

MW: Definitely. What is a big plus for us is that humans have absolute trust in computers. That's a bit difficult in optometry. People come and ask “Well, are they all opticians?” - then of course you can say “Sure, we are all optometrists and masters”. But of course the older ones are always a bit skeptical. But when they see these high-tech machines that measure the eye to a tenth of a millimeter - then at the latest they are also convinced.

ML: I have already talked about your glasses and was asked, “Do they do an eye test like the one we know from a doctor or do they do a quick test like I've done at another chain store?” How does it look because your eye test looks like?

MW: Well, first of all I want to clear up one thing without making the ophthalmologists bad. Eye examination is not the job of the ophthalmologist! It has never been. The ophthalmologist - I took lessons from an ophthalmologist - learns the eye test for two weeks in the standard course. A good master optician deals with it for three years at a time. The whole background knowledge is therefore considerably greater. In connection with the knowledge of the capabilities and properties of the lenses. At the latest then it stops with the ophthalmologist, because he simply doesn't know which glass can do what. We can of course also do a classic eye test, but that costs us a lot of time and no longer fits into the concept, the price structure would no longer work. But today's machines are so precise that they can get the measured value very, very precisely at a glance. This is the so-called objective eye test. And then we only have to measure briefly, which normally only takes ten minutes and then we have a one hundred percent reliable value. A lot of research has been done in recent years: Which eye test sequence is ideal? Which optotypes do you use for this? If you've found the right way and everything has been programmed so that it goes well, you can get a complete eye test done in ten minutes.

ML: I was pleasantly surprised when I suddenly had such a machine on my head. It actually works quickly and without much bloodshed.

MW: None of this is a new invention. This is simply a beam of light that is shot into the eye and based on the reflection of the light on the retina, the machine can calculate which lens is needed. As an optician, you usually learn that with a retinoscope, a kind of modern flashlight. With it I blink a little in the eye, see the reflection on the retina and if I then have a certain flicker, then I know which lens I need. You can use it to do an eye test very, very precisely. This is usually still done in the third world, where either people cannot read or where there is a language barrier. With a little practice you can get a good eye test with a retinoscopy in maybe 15 or 20 minutes, with which you can get people to 100 percent vision.

ML: But that's probably also necessary, isn't it? Because people probably just lie in the best doctor house fashion. I noticed that too. You let me read this letter card and if you can't see completely badly, then you can still guess your way relatively far.

MW: Due to the digital media, the visual requirements have also increased massively. In other words, what was still great 20 years ago is no longer accepted in any way by customers today. What glasses I built 20 years ago is hair-raising today. Back then, everything - viewing height, eye relief - was somehow built in and finished. This is simply no longer possible today because the visual requirements are so high that even the smallest detail is massively disturbing. Seen in this way, ophthalmic optics has also become massively more precise over the past twenty years.

ML: I have another fundamental question that comes to mind: After we finished the test, you told me that I would get around 110 percent vision with the lenses. How is that possible? Why is that more than 100 percent? I've never understood that before.

MW: When it was decided what 100 percent eyesight is, let it be 100 years ago, people weren't as fit as they are today. Diet and so on make a massive contribution to whether I can see well or not. They said: you have to be able to see two points separated from each other at a distance of six meters. The points are two angular minutes apart. If you see the two points six meters apart, you have 100 percent eyesight. When the eyesight deteriorates, the two points merge into one point. Then there are people who can only see the two points from a distance of three meters - they then have 50 percent vision. Then there are people who see the two points not only from six, but also from twelve meters away - they then have 200 percent eyesight. That's why you can have more than a hundred. Nowadays, a normal person usually achieves at least 100 percent, usually even 120 percent. So a young person up to 25.