Polycarbonate index question

[borisvodofsky]

So, I decided to order glasses on the internet. LOL mistake maybe..:sneaky:

I feel like it would be so easy to scam customers, because no one can actually verify that they got the extra' higher lens index number they paid for..

Anyway to tell??

I ordered one pair with 1.57, and another with 1.67, just to make sure they're not TOTALLY fucking me.. I realize that they could still give me 1.51 and 1.62, while I would see a difference, I'd still get robbed..

 

[borisvodofsky]

I can't exactly shine a laser to it and measure the angle of refraction can I?

 

[Matthiasa]

Umm you probably could as long as you knew the rest of info for it.
Or you could get it tested but that would probably cost more then what yo saved getting it online.

Or you could just put them on and see how your vision is, getting glasses stronger then you need is bad for your eyes.

 

[PottedMeat]

besides the thickness? not really.

 

[PlasmaBomb]

^ I presume he is talking about refractive indexes... which would affect how thin the lenses were?

 

[borisvodofsky]

^ I presume he is talking about refractive indexes... which would affect how thin the lenses were?

Yes, That is what I am talking about..

This is just how little faith I have in others.. LOLOL,, jkjk,, i have faith in ATOT

 

[PottedMeat]

I can't exactly shine a laser to it and measure the angle of refraction can I?

i bet you could, but you'd probably need some pretty accurate measurements of the shape of the lens in the first place.


if your eyes aren't that bad you probably wont be able to tell the difference.

 

[Bignate603]

Yes, That is what I am talking about..

This is just how little faith I have in others.. LOLOL,, jkjk,, i have faith in ATOT

Well, there's your problem.

In all seriousness, if you get the glasses, the lenses aren't too thick and they look good why would you care?

 

[borisvodofsky]

i bet you could, but you'd probably need some pretty accurate measurements of the shape of the lens in the first place.


if your eyes aren't that bad you probably wont be able to tell the difference.

Hmmmm.... spray the lens with something,, then use a 3d scanner? that WOULD work.. hehehe... now to go borrow stuff from the school... muahahahahahahaha.....

Where would I get a thin enough laser beam, can't exactly Borrow an entire laser assembly.. mmmmm... ughh.. that's my problem now.

 

[borisvodofsky]

Well, there's your problem.

In all seriousness, if you get the glasses, the lenses aren't too thick and they look good why would you care?

Yes,, if you get a fake Picasso for 20 million, but it's a dame good painting,, it's still worth it.. I understand the logic,,, but there's this deep seated pulse for vengeance...D:

This is a cause of depression no doubt...:'( <---- do i file this under obsessive compulsive?

 

[DrPizza]

Actually, it's pretty simple to check. You just need a liquid with the same index of refraction. I'm sure someone's got some sort of equipment that makes the process pretty easy, but you don't have that equipment. And, I'd think it would be pretty damn difficult to use Snell's Law with a pair of glasses to measure the index accurately enough.


Wow, I couldn't think of any common liquids with an index that high; googled and struck out there also. Looks like you'll have to order some liquids then.
http://www.cargille.com/refractivestandards.shtml
You could get a whole set & then measure your index of refraction to within .001. It's been 25 years since I did any of this stuff; for some reason, I'm thinking you're going to need a polarized microscope. That seems to ring a bell. That, plus $2000 for the standard refractive liquids.

Personally, if the lenses matched my prescription & looked nice, I wouldn't care. Unfortunately, I cannot wear high index polycarbonate lenses; I'm overly sensitive to the chromic abberations.

 

[borisvodofsky]

Actually, it's pretty simple to check. You just need a liquid with the same index of refraction. I'm sure someone's got some sort of equipment that makes the process pretty easy, but you don't have that equipment. And, I'd think it would be pretty damn difficult to use Snell's Law with a pair of glasses to measure the index accurately enough.

Ohhhhhh...oooooooooo... Why did I not thinks of that... I concede to your smarts.

Yes, I am sure I can borrow such liquid from my school. Fingers crossed zennioptical doesn't rape me up the ass.

 

[borisvodofsky]

Actually, it's pretty simple to check. You just need a liquid with the same index of refraction. I'm sure someone's got some sort of equipment that makes the process pretty easy, but you don't have that equipment. And, I'd think it would be pretty damn difficult to use Snell's Law with a pair of glasses to measure the index accurately enough.


Wow, I couldn't think of any common liquids with an index that high; googled and struck out there also. Looks like you'll have to order some liquids then.
http://www.cargille.com/refractivestandards.shtml
You could get a whole set & then measure your index of refraction to within .001. It's been 25 years since I did any of this stuff; for some reason, I'm thinking you're going to need a polarized microscope. That seems to ring a bell. That, plus $2000 for the standard refractive liquids.

Personally, if the lenses matched my prescription & looked nice, I wouldn't care. Unfortunately, I cannot wear high index polycarbonate lenses; I'm overly sensitive to the chromic abberations.

I just asked my friend to order the 18005 5th set. only 470$, that should be enough to get between 1.52 and 1.67 at .01.

Misappropriation ftw..

Thanks alot.

 

[DrPizza]

If you have access to stuff like that at your school, you probably have access to a refractometer. Just use that.

 

[borisvodofsky]

If you have access to stuff like that at your school, you probably have access to a refractometer. Just use that.

It's hard to borrow things that I'm not familiar with, or know exactly where to find, or a person who knows how to use it..

This liquid'll have to do, since it's pretty straight forward what I gotta do. hehehe. :thumbsup:

The time that it'd take for me to get all the stuff, is the major inconvenience, so it's best to throw money at it.

 

[DrPizza]

IIRC, some of those liquids might stain your lenses. "Hey, look! They did have an index of refraction of 1.70. Now they're yellow/orange stained.

 

[borisvodofsky]

IIRC, some of those liquids might stain your lenses. "Hey, look! They did have an index of refraction of 1.70. Now they're yellow/orange stained.

http://www.polywater.com/cracking.html

You scared me for a sec.. but, hope all is good.. at least i ordered 2 pairs .. hahaha

I will do quick soaks and rinse.

 

[Sho'Nuff]

Try this: http://www.pl.euhou.net/docupload/f...undUs/IndexOfRefraction/IndexOfRefraction.pdf

 

[MikeyIs4Dcats]

you know you can generally just take them to your optometrists office and ask them to check them

 

[Kaieye]

I own a optical lab and process a lot of poly, etc etc. It has a hollow high pitch sound when you drop it on a hard surface compared to plastic.

1.6 and 1.67 materials tend(but no always)to be around 1.1 to 1.3 mm center thickness when you measure it at the optical center of a minus lens.

Sometimes the Dr. asks me what material the old lenses that are sent to me to duplicate and I normally don't have too much problems with that.

Someone here says that if it looks thin, live with it. I agree..

 

[SpatiallyAware]

This is why I buy my glasses at Costco. I love Costco.