Manufacturing our own spectacles?

Manufacturing our own spectacles?
The price of lenses seems to have sky-rocketed in recent years and it seems to me that we might
be well-paced to manufacture our own spectacles after we are given a copy of the prescription.
We have cutting, grinding and polishing equipment equipment, and given a supply of acetate sheet could be well-placed to save ourselves a few shekels.
Perhaps those with XNX milling facilities would find it even easier?
Checking the truth of what we produce should be straighforward with the use of a laser pointer and a protractor to check the angles of refraction.
Those equipped with Tool & Cutter Grinders will already be in possession of necessary angular calibrations!
As for the frames, are we not already expert in producing miniature and rugged fabrications? Even the clock and watchmakers among us will have the necessary taps and dies for the hinges!
So, who has the necessary background to convert prescription numbers into radii of curvature for lenses?
Perhaps there are already CAM programs available for this application? What do commercial opthamologists use for this very purpose?
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All this for 15 quid a pair ?
John S.
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John S wrote:

Damn! My last prescription pair cost me 16!!
Bob
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Bob Minchin wrote:

Aaargh. 465.
They are impact-resist, scratch-resistant, anti-glare and extra-thin and lightweight though, and have lasted 10 years. FCUK frames, but not terribly fashionable.
The lenses cost 155 each, they were about 2-1/2 inches round to start, and the lady in the shop cut them to size to fit in the frames.
-- Peter Fairbrother
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Peter Fairbrother writes:

Dear brother metalworker, you are simply getting fleeced.
But them from http://www.zennioptical.com/ for $19.
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wrote:

No. A member of my family has just had to shell out 240 to Boots for a pair of vari-focals.
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Derek wrote:

Have you looked at the numerous online spectacle services? Varifocals are dearer than single focus lenses but there is absolutely no need to pay 240. Glasses are normally posted in a few days and are made in UK with a huge choice of frames.
Bob
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wrote:

absolutely
huge
Bob,
I've not found any online sources of plastic varifocals with astigmatism correction and reactolight features - do you know of one? My last pair cost a packet from Boots and it's really time for a new prescription - I'd just love to have the eye test then walk out with the prescription !
AWEM
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On Mon, 5 Jan 2009 19:47:09 -0000, "Andrew Mawson"

Er indoors has a complex astigmatism correction and has had plastic light sensitive lenses from http://www.optical4less.com/ for some years and is very happy with them.
A trick I also found useful is to add a few diopters to your normal reading prescription to get a pair of prescription magnifying glasses - ideal for detailed work.
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On Sun, 04 Jan 2009 05:15:19 -0800, John S wrote:

My bifocals cost around £80 - 90 per pair and that is before frames and non-glare coating etc.
--
Neil
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>

Does the acetate you have access to have a known, repeatable, and consistent refractive index? (There is a difference between "any old bit of acetate" and optical grade plastic.)
Having said that, an interesting project for you. I look forward to you reporting your progress.
Brian
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You have misinterpreted the start of a technical discussion to investigate possibilities as though it were a definite commitment.
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On Mon, 05 Jan 2009 07:41:32 +0000, Derek wrote:

That is what it sounded like.
--
Neil
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On Sun, 4 Jan 2009 11:13:21 -0000, the renowned "Derek"

I think the opticians typically buy uncut lenses (60mm diameter?) and then cut them to fit the frames using a special machine. They don't actually grind the optical surfaces of the lens.
A quick web search finds this:
Google book search will let you look at some pages inside: ISBN-10      0750688947 ISBN-13     9780750688949
(try this url: http://tinyurl.com/a7vjev )
You can get very inexpensive eyeglasses from China these days, made to your prescription.
Opticians generally have a retail business to run, insurance often pays for the glasses (so cost isn't important unless it rises much above $500 or so), and frames are often essentially a jewellery item which people are willing to splurge hundreds of dollars for. The actual cost of generic lenses and frames is very, very low, but if you want Armani + Oakley etc. you must cross their palms with silver.
Best regards, Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
snipped-for-privacy@interlog.com Info for manufacturers: http://www.trexon.com
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Spehro Pefhany wrote:

Read an article this last year that compared several sources for prescription lenses on price and how close the lens matched the prescription. Since I don't remember for sure, the name of the big chain outfit included, I won't mention/guess. But Costco came out well on top both for price and accuracy in meeting the prescription. Cost savings on one pair of glasses could easily cover a basic membership.... Don't know if UK has any Costco outlets, but there's plenty of them here in the States.
Jon
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. But Costco came out well on top

No we have web sites like www.specs4less You fill in the form pay your 20 quid, used to be 15 and 2 days later you get a new set of specs thru the door.
Glasses direct has them for 15
I use these for work and when they get shagged just get a new pair.
John S.
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On Sun, 4 Jan 2009 08:52:12 -0800 (PST), John S
That link seems to be not working...another victim of the crunch?
Regards, Tony
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wrote:

...or did you mean http://www.spex4less.com /
Regards, Tony
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Yup that's them. I did get a bad set once, one lens was totally wrong, rang them up and explained and they aked me to email the pescription thru again and sent a new set out by return, no extr chage and told me to throw the old set away. Can't fault that for service, I always think it matter how someone gets over a problem that counts.
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On Sun, 4 Jan 2009 08:52:12 -0800 (PST), John S

The safety glass frames seem to be 70 quid though...
Apparently I now need safety glasses and hi--vis jackets to visit power stations to do IT work, even though we didn't need them when I was building and commissioning the same stations :-|
Mark Rand RTFM
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