Tech Prescription Sunglasses in Japan. How to...

D'Pioneer

Far beyond the black horizon
Oct 9, 2015
458
229
83
#1
Over the past few years (yes, years), I have been on a quest to find a place in Japan which will make me prescription sunglasses to the spec I require.

This has been a mission of frustration and annoyance, every step of the way, but I have finally figured it all out. The following info should be of use to anyone else needing to do this, and should go some way to preventing you going through all the hassle I have.

First up then, what are the main options for getting prescription sunglasses?

There are two ways to get prescription sunglasses. The first way, is to remove the original lens from the sunglasses frame, and replace it with a lens which includes your prescription, and also has UV cutting properties, and a darkening property. The second way, is to keep the original sunglasses lens, with its inherent sun cutting properties, colour, etc., and put inserts behind it which match your eye prescription.

The first way, is I feel preferable for cycling sunglasses, as an insert set up means there are two lenses to get covered in sweat and clean. For some people, a single lens is not possible, but I urge them to check out the place I mention at the end of the post, as they might be able to do single lenses where others have said no.

So, with the vast number of glasses shops in Japan, what is the problem with getting prescription sunglasses?


There are a number of issues...

One... First and foremost, most glasses shops in Japan don't have a clue about the technicalities involved in making up prescription sunglasses. All of the high-street shops you see, like Coolens, Megane-Super, JINS, etc., focus on selling cheap frames, with standard regular clear prescription lenses in. This business model is based on selling high volume standard items. A shop in Japan will have a large range of frames, but these frames will all have a very similar lens profile; a flat lens, with an oval shape. This means the staff in the shop can do a quick eye test, then look through a massive drawer of lenses in little paper slips, pull out which one you need for the left and right, put them in the frames, take your money and send you on your way. This is great if you want regular glasses, but there is nothing here to deal with sunglasses. The lenses they put in are usually cheap stock items, with the occasional 'chance' to upgrade to a Nikon lens. It is all very rigid and not open to any flexibility.

Two... The staff in the shops are untrained past doing the basic work outlined in point 1. The demand for prescription sunglasses in Japan is very very low compared to regular glasses, so when asked about the possibility of making them up, they just do that fucking head tilt, air suck thing, and want you out the shop asap, because they don't have a single clue about the subject. This is very annoying indeed and has happened in basically every single shop I have been in, which is basically all of them. Even when they show a slight understanding of the subject, it never gets further than them incorrectly saying that they can't put prescription lenses in certain frames that you pick up and show them (even when there is a sticker on the lens saying it is possible), then getting shirty with you for questioning their 'supreme knowledge', even though they are utterly wrong.

What are the technical issues with creating prescription sunglasses lenses?


Creating a prescription sunglasses lens is more complex than a standard glasses lens for a number of reasons.

One... Sunglasses usually have a greater base curve to the lenses, especially wrap-around frames which are normal for sports styles. This means that standard flat lenses can not be put in and the lenses need to be made especially for the frames. This is bespoke work. The base curve for lenses have a rating number, from 2 to 9...



8 curve is usually the highest curve that a prescription can be made for. If the sunglasses have a curve higher than 8, you simply can not do it, and need to choose a different frame. The biggest challenge with curved lenses is maintaining a constant flat view through the lens at all angles for the wearer, which is an ultra fine balancing act of extreme precision, and becomes exponentially more delicate, the higher the base curve. Base curve 8 is the highest curve possible while maintaining a flat image, basically, which is why it is the cut off point for prescriptions. It may be possible to make a higher base curve lens, but there would be a chance that it would distort at the edges.

There is another issue here too, in that the worse your eyesight is, the lower the maximum base curve you can get a prescription to fit. Each lens manufacturer has their own guidelines and charts to use to work out the maximum curve possible, for a certain prescription. It looks a bit like a BMI chart.

Two... As well as the base curve, the actual size of the lens itself affects the ability to make prescription lenses. The bigger the lens, the more difficult it is, as the angle between the very edge, and the centre of the lens gets larger as the lens size increases, which increases the chance of distortion.

Three... Getting more specific, in order to work out the maximum base curve possible, we need a number of measurements.

The first, is the left and right 'Sphere'. For short sighted people, this is a minus number, and will be different on the left and right. Mine, for example; R= -2.75, L=-2.50.

The second number is the PD or Pupil Distance. This is the distance in mm between the centre point of your left and right pupil when looking forward. Mine, for example is 68mm.

Once these two numbers are found, the lenses are measured whilst inside the frame, to find the pupil centre point of each lens (using the PD number as reference), then the distance between this centre point, and the outside edge of the lens is measured.

This number is then doubled, and referenced against the manufacturers compatibility chart to see if that particular lens size, at that particular base curve can be made, at the prescription strength required!

If, by some miracle of luck, everything works out, and you can actually get a lens made in the base curve required, with your PD and Sphere falling within the acceptable boundaries of the lens manufacturers guidelines, you then move on to choosing things like UV cut %, outer finish (mirror, graduated fade, etc.), lens colour and so on.

If you have read this far, you will I am sure realise that this kind of knowledge is way over the head of the average 1,000yen per hour Megane shop worker. I found this out in typical passive aggressive fashion, with responses to my questions ranging from blank stares, to cocky comments about this not being something that Japanese people ever buy or get made. Yeah, I know, pricks.

More technical issues...


There are other restrictions to getting prescription lenses made...

-The left and right lens must be separate. You can not buy a prescription 'shield' type lens (yet). Oakley actually make their own prescription lens 'implants' for their range of sunglasses like the Jawbreaker which do this, which are basically an extra lens bonded to the back of the standard lens, in a kind of halfway house between a prescription lens, and an insert system. This is fine if you want Oakleys but they are the only manufacturer who does (well, they are the only 'brand' made by Luxottica who Luxottica does this for)

-The lenses need to be fairly 'standard' shape. They can not have any sharp angles, cutout sections, etc., as this would affect the prescription, and the third party lens manufacturers are not willing to cut shapes that specific.

So what do you do about this then?


With all this in mind, you have a few options...

-Go with Oakley. They offer a prescription lens system. The issue here is that for some people, Oakley do not fit their face (me, for example), and the 'Unobtanium' frame material can not be adjusted to make them sit straight on your face. This is not such a mega-issue if you are using a standard non-prescription lens, but with prescriptions, you need the glasses to sit bang straight on your face, or you get all kind of warping, distortion, etc, which can lead to headaches.

-Get your prescription and order from abroad. FramesDirect in the US is very good, but the problem there is you get no after service, like you would do from a local shop, and also you can't try the glasses on first. You can always try on the frames you want in Japan, then order from FramesDirect, but again, it is not ideal.

-Find a place in Japan who actually know what they are talking about, and know all of the above information. This is the option I have been searching for, for ages and ages, and I honestly thought that no such place existed.

I did find a place though!

GlassMania in Aoyama.

They have a direct contract with HOYA lenses, which are a Japanese lens company making aerospace optics. They are the only place I have found who can make the 8 Base Curve, Polycarbonate, 25% cut, Silver Mirror, 67mm wide lenses I have been looking for.

So, with all that said, if you are looking for prescription lenses for sunglasses and don't want to deal with the usual no brain brigade, and come out empty handed, check them out. They are on Instagram, FB, etc., and the guy in the shop speaks English.

My dreams of getting Andrew Eldritch aviator prescription mirror shades is now a reality.
 
Likes: shonanmike

andywood

Maximum Pace
Apr 8, 2008
1,681
1,316
133
Niigata
#3
I used to use Rudy Project with a prescription insert behind the sunglass lens.

The advantage of this is that you can change the sunglass lens in seconds depending on the weather or time of day you ride. The sunglass lens also flips up so you can see better in tunnels or if you get caught out in the dark.

The disadvantage like @D'Pioneer says is more parts to get messed up. I also found RP's nose pads to go all gunky and other metal parts to rust easily.

I quit those and bought some prescription sunglasses from high street chain JINS a few years ago. I've been really happy with them. Aimed at the cycling/golf market. Cheap. All plastic so go straight into the shower with the helmet after a ride. You can choose lenses. I chose a lens that works well for dark starts but also offers protection in sunlight.

Again like @D'Pioneer says, these may be limited if you have a strong prescription. But worth a look if you are in the market.

Andy

www.jyonnobitime.com/time
 

Musashi13

Maximum Pace
Aug 27, 2012
1,774
1,105
143
41
Ichikawa, Chiba
#4
Good detective skills. I am sure this will help a lot of people.

I will be getting a guide ferret soon or an ape of some sort to help me cross the road in the not too distant and the cycling world will mourn my passing.

L = +6.75 R = +7.50 with a major astigmatism in both since birth

There are lots of skilled opticians in Japan but unfortunately there are far too many bad eyes and it means the majority of high street dealers are under-qualified and basically don't care about your "niche needs". You can find a solution and the technology only gets better. Rudy Project have done me right where Oakley failed but nothing sees better than my contacts, which I would wear if it weren't for the pain that comes with the sweat and sun cream streaming into them on anything more than a shopping trip.

Nice work @D'Pioneer
 
Likes: D'Pioneer

PSB

Maximum Pace
Oct 26, 2014
113
66
58
Tokyo
#7
I am currently using some from JINS based on previous advice on this board, but my sight is so bad that they could not do curved lenses - so the style I got is a bit naff. Makes me look like Joe90 if you are old enough to remember him!
 

nishiki2013

http://www.bikepackingjapan.com
#9
Great info. I'm tired of coughing up for contact lenses every few months (that I only use for cycling). A pair of subscription sunglasses would be ideal, but I also hit a brick wall the first time I asked and immediately gave up.

Slightly off topic, but I once had a Japanese cycling friend who bought a pair of 'cycling' prescription glasses and spent the majority of his first ride wanting to throw up due to wacky eyesight distortion.
 
Likes: D'Pioneer

Musashi13

Maximum Pace
Aug 27, 2012
1,774
1,105
143
41
Ichikawa, Chiba
#10
It seems that if the lenses are curved and you don't pay top dollar for the best a man can get they have the effect of making you sea sick (as stated above). The optician asked me again and again if they made me feel dizzy, he made me promise to bring them back if I felt ill wearing them. I didn't. They cost enough and I'm glad I paid it.