Author Topic: Stick-on bifocal lenses  (Read 5140 times)

Stick-on bifocal lenses
« on: July 06, 2014, 10:48:08 am »
As I find it difficult to read a routesheet or a Garmin screen on the move, and reading specs perched on the end of my nose are not ideal, I've been looking for alternatives. There appear to be a couple of choices of sports/cycling specs with lensed sections, but I like photochromic ones which don't appear to be available.

I have bought a set of Hydrotac stick-on lenses. They're soft semicircles that are applied wet and pressed into place with tissue. Once dry they are firmly attached but can be peeled off with a fingernail. You can cut them to shape with scissors.

I tried them last week over a 600k routecheck. So far I'm impressed. Despite the specs getting quite smeary with sweat and being cleaned under a tap the lenses stayed put. Optical quality isn't perfect - I found the edge blur irritating reading a newspaper - but for narrow focus on a routesheet and Garmin they worked unobtrusively.

It took a few attempts initially before I was satisfied with the adhesion and I'll probably fine-tune the shape at some point.

They're American made. Googling 'Hydrotac UK' brings up British retailers. There appear to be other makes though a few reviews suggest these are not as good.

LEE

  • "Shut Up Jens" - Legs.
Re: Stick-on bifocal lenses
« Reply #1 on: July 07, 2014, 09:08:38 am »
Are they available in Car Windscreen size?
Some people say I'm self-obsessed but that's enough about them.

T42

  • Old fool in a hurry
Re: Stick-on bifocal lenses
« Reply #2 on: July 07, 2014, 09:16:16 am »
Been looking for something like this for quite a while. I can read my counter over the top of my glogs but only at risk of losing them.

Curiously, googling "Hydrotac France" brings up an aerogel bandage (which must be quite uncomfortable to the oesophagus). Amazon.uk to the rescue.

Thanks for the tip !
I dare eat all that may become a man.

But hold the oysters.

Re: Stick-on bifocal lenses
« Reply #3 on: July 08, 2014, 10:48:39 pm »
Here's a photo.


Re: Stick-on bifocal lenses
« Reply #4 on: July 08, 2014, 11:47:20 pm »
These look worth a punt - so how to know what strength to choose? They come in +1.50, +2.00, +2.50 and +3.00. I have a prescription that says 'near add +2.50' for each eye - is this the strength I need?

hellymedic

  • Just do it!
Re: Stick-on bifocal lenses
« Reply #5 on: July 09, 2014, 12:33:50 am »
These look worth a punt - so how to know what strength to choose? They come in +1.50, +2.00, +2.50 and +3.00. I have a prescription that says 'near add +2.50' for each eye - is this the strength I need?

It would be if you think your maps and route sheet are to be read at your normal reading distance - usually about 35cm - from your face.

Chances are that these items are 50-60cm from your eyes and weaker reading correction may be more appropriate.
Experiment by combining your distance specs with some ready readers of around +2 at route sheet distance.

Re: Stick-on bifocal lenses
« Reply #6 on: July 09, 2014, 01:34:11 am »
These look worth a punt - so how to know what strength to choose? They come in +1.50, +2.00, +2.50 and +3.00. I have a prescription that says 'near add +2.50' for each eye - is this the strength I need?
I'd go for +1.50 myself, so I could read the GPS but not damage my view of the road surface so much. It does depend on how close you want to peer at detail though.
I can function OK outside with +1.5 reading glasses on, and even read car number plates at double the legal driving distance.

Diopters go like the reciprocal of the focus distance in meters, so +1 brings your long distance vision from infinity down to 1 meter, +1.5 brings it down to 67cm, +2 brings it down to 50cm, and +2.5 brings it down to 40cm. Beyond these distances what you see will be more or less blurred.

If I assume that the closest you can normally focus on something is just beyond arms length, at 1m, then your eyes have an accomodation of 1 diopter. That means that through +1.5 hydrotac lenses, your focus range will be from 1/1.5m (67cm) to 1/2.5m (40cm). If your normal closest focus is a bit less, 80cm, your accommodation is 1.25 diopter, and +1.5 lenses will give focus down to 1/2.75m (36cm).

Re: Stick-on bifocal lenses
« Reply #7 on: July 09, 2014, 11:37:40 am »
Excellent, thank you both. I want to be able to see the gps - I can just about make out the larger figures at the moment but have to peer over the top to see anything with clarity. So, yes, it’s the distance to the gps rather than 35cm which I now see is what that +2.50 figure relates to (that said, I can read perfectly well without glasses, which I did tell the optician!). Likewise, when driving - I can make out the speedo, but the radio is a blur, so I'm hoping this will deal with that as well.

Re: Stick-on bifocal lenses
« Reply #8 on: August 06, 2014, 12:20:22 pm »
Update: lenses still attached after a 600, a 24hr, and sundry other rides. Specs have been washed and wiped several times without a problem. Gets 4.5 stars from me.

Hint: choose a slightly lower diopter than your normal reading glasses.

Re: Stick-on bifocal lenses
« Reply #9 on: May 26, 2015, 04:18:14 pm »
To add, somewhat belatedly (though eye problems rarely improve, so I'll consider this appropriate !)
Try these:
http://www.straightlines.com/safetyspecs/?product=bi_focal_safety_glasses

I've bought several pairs (smoke, clear and yellow are the standard versions) and they are basically safety specs, in a kind of "cycling" type shape. But they have a "reading-section" cut low in the polycarbonate lens (varying corrections available).
The best thing is, they cost about £9 a pair !! (they used to offer "3 pairs for £25) making them IMHO fairly disposable, with no worries about adhesion, falling off etc. (I have tried the stick-on versions, but find these more suited to my needs).
Not custom Oakleys perhaps, but then you can buy roughly 30 pairs for what they charge for Oakleys !!
Alistair (pieeater) Dulwich Paragon

windy

  • Sitting on a bog in the North Atlantic
    • My Instagram

Re: Stick-on bifocal lenses
« Reply #11 on: May 26, 2015, 06:08:43 pm »
I've just ordered some of these:



I wish I would have known last week, otherwise I wouldn't have ordered some of these:

Re: Stick-on bifocal lenses
« Reply #12 on: May 26, 2015, 08:04:49 pm »
Perfect timing chaps as I was looking for this thread as I need some of the above mentioned specs to reduce the number of specs I currently have to carry.

Re: Stick-on bifocal lenses
« Reply #13 on: May 26, 2015, 08:10:17 pm »
I've just ordered some of these:



I wish I would have known last week, otherwise I wouldn't have ordered some of these:


There is an advantage with the latter in that you can attach them to lenses of your choice, including, as I have, photochromatic.

Re: Stick-on bifocal lenses
« Reply #14 on: May 29, 2015, 10:24:32 pm »
These arrived today. They fit really well around my face and the magnification is fine.

Re: Stick-on bifocal lenses
« Reply #15 on: March 13, 2017, 09:08:00 am »
I've just bought some of these, based on Ian's glowing review. 

First of all they wouldn't stick as my lenses are too curved.  A bit of googling suggested that dipping them in hot water (not boiling) first might help, and it looks like it has.  One is sticking as I write. 

However, they are a bit big (or my cycling lenses are quite small) and I only need a fairly narrow bit of vision for GPS / phone when on the bike.  I think I am going to trim them pretty radically: anyone have any tips before I get the scissors out?

Re: Stick-on bifocal lenses
« Reply #16 on: March 13, 2017, 10:09:42 am »
I cut mine down.  I'd probably flatten the crescent to move them down.

However (sorry Frank)  since then I have found several manufacturers making specs with integral lenses—and, importantly, photochromic.

BSG-49PH Sport Glasses are the one I have.  Seem to be retailing for less than £40.

Re: Stick-on bifocal lenses
« Reply #17 on: March 13, 2017, 12:51:29 pm »
Thanks Ian.  I need mine for Wednesday morning, no time for alternatives! 

I took about 5mm off the flat edge and they work pretty well.  The curve actually fits into the bottom of my frame pretty well so won't touch that. 

Will probably trim maybe 5mm off the outer edge too.  ATM I could read something on my brake hoods while crouched on the drops, so that is more width than I require!