1.74

**mrba** · 03-21-2004, 04:08 AM

Hello All,

Heres a question for those of you in the know. 1.74 Hi Index plastic lenses are available in the rest of the world but not here. I saw a few years back optima even released it in the frame facts lens book, and then later didn't release the product.

Does it not pass drop ball?
Are the optics terrible?
Is it illegal?

Where can I get some? :D

**For-Life** · 03-21-2004, 11:37 AM

mrba said:
Hello All,

Heres a question for those of you in the know. 1.74 Hi Index plastic lenses are available in the rest of the world but not here. I saw a few years back optima even released it in the frame facts lens book, and then later didn't release the product.

Does it not pass drop ball?
Are the optics terrible?
Is it illegal?

Where can I get some? :D

I do not know if it passes the drop ball test. I do know it passes Canadian regulations, which are not as strict as the American ones. The optics are great. It actually has a higher abbe value than poly and 1.67 (I think a 38 value, but I do not have any material right here right now confirming that). It is certainly not illegal in Canada.

**Jacqui** · 03-21-2004, 04:35 PM

I bought some from CLEX in Korea, semi-finished. My partner loves them.

**Clive Noble** · 03-24-2004, 01:05 AM

We're getting stock finished S/V here.... lovely lens, not the cheapest, but quite frankly I don't see a lot of difference, up to say -8.00, between that and 1.71

**LENNY** · 03-24-2004, 10:25 AM

How about 1.74 and 1.67 aspheric?

**mrba** · 03-24-2004, 12:40 PM

Clive,

**mrba** · 03-24-2004, 12:42 PM

Clive,
The difference is the dark side of the force in the US. Also the difference between 1.70 and 1.67 is next to nothing. And if you consider that most 1.70 has to be surfaced, it is possible that 1.67 (mostly stock and 1.0 thin) is actually thinner.

Anybody know where I can get some 1.74?

**For-Life** · 03-24-2004, 10:26 PM

Nikon sells the Nikon 5 which is a 1.74 with HCC or HCC ICE. They also have it in their priemer progressive the Nikon i. Both lenses are very good lenses.

**Eddie G's** · 03-25-2004, 10:09 AM

I have been using the Centoptic 1.74 AR lens for about a year now and have NO complaints.

Apparently they are made in the same factory as the Nikon's but are cheaper at Centennial for $160/pr Cdn (+ your discount).

The only thing I don't like about them is when I edge them they REEK of burnt onions!!!

**Pete Hanlin** · 03-26-2004, 12:00 AM

Regarding 1.74, it is my understanding that two companies have been producing the 1.74 product that is being used in the ophthalmic market (they are both Asian companies- I can look up the names if anyone cares).

Anyway, the two companies were engaged in a patent battle- which was settled a few months ago. As a result, some of the companies which purchased lenses from the losing company may be losing the rights to the 1.74 material.

The reason the product smells "like onions" (or, more specifically, like sulfur) is the sulfur content- which is about 70%. By comparison, 1.67 lenses have slightly less than half the sulfur content. I also understand there are several properties that make the 1.74 material an attractive substrate for the ophthalmic market.

As for availability, all that can be said at this point is that they will be available for the US market eventually- but don't hold your breath (save the breath holding for when the lenses arrive and you have to edge them ;^).

**keithbenjamin** · 04-05-2004, 08:11 PM

Regarding 1.74, it is my understanding that two companies have been producing the 1.74 product that is being used in the ophthalmic market (they are both Asian companies- I can look up the names if anyone cares).

I'd like to know.

Thanks

-KB

**mrba** · 04-05-2004, 08:27 PM

I found the answer myself on this one. I met with the companies at Expo. They are not willing to import it because the patent issues have been resolved everywhere but in the US. It will not get through customs.

**keithbenjamin** · 04-05-2004, 08:40 PM

We were contacted by a company in Taiwan called Mildex saying they'd like to sell us some 1.74. Now there is no mention of it on their website. I was wondering, if they were one of the two.

-KB

**Pete Hanlin** · 04-06-2004, 12:06 PM

Sorry to have been away for a while- I've been traveling a bit lately...

As I recall, the two companies who have worked with 1.74 resins are Mitsui and Mitsubitsi Gas Chemical. I don't recall which company won the suit, I just remember there was only going to be one supplier and that the supplier had issued "cease and desist" orders to the other companies selling the substrate.

At issue was who owned the patent to the material. Theoretically, I suppose there could be a number of companies who have sold 1.74 lenses. However, the actual resin came from one of two suppliers.

**Eddie G's** · 05-10-2004, 01:30 PM

Just received a FLYER with my Zeiss Lenses this morning stating...

Clarlet 1.74 AS is now available.

These are stock uncuts and they include the Carat XT arc.
-3.00 to -10.00 SPH up to a -2.00 cyl.