MR-10 drawbacks?

**Iakwin** · 06-02-2005, 01:05 PM

Hi All!

m new here!

If i may ask, are there any drawbacks to this material, MR-10, besides its low ABBE?

**drk** · 06-02-2005, 01:36 PM

Originally Posted by Iakwin

Hi All!

m new here!

If i may ask, are there any drawbacks to this material, MR-10, besides its low ABBE?

Higher cost!

**Darryl Meister** · 06-02-2005, 06:54 PM

MR-10 is essentially a newer version of the MR-7 1.66/67 high-index lens material, with a few subtle improvements. Both materials offer relatively good heat, chemical, and impact resistance (though poly would still be a better choice for impact resistance). Both materials also offer excellent tensile and flexural strength. And, of course, they both of a very high refractive index and relatively low density, with an Abbe value that's still better than Poly's.

Best regards,
Darryl

**Iakwin** · 06-04-2005, 07:28 PM

Originally Posted by Darryl Meister

MR-10 is essentially a newer version of the MR-7 1.66/67 high-index lens material, with a few subtle improvements. Both materials offer relatively good heat, chemical, and impact resistance (though poly would still be a better choice for impact resistance). Both materials also offer excellent tensile and flexural strength. And, of course, they both of a very high refractive index and relatively low density, with an Abbe value that's still better than Poly's.

Best regards,
Darryl

Thanx for your reply

Hmmm.... so MR-10 has a lower impact resistance than poly?

but, I read from the Seiko website that their MR-10 1.67 lens are stronger than poly.

Besides Seiko, who else is using MR10 ?

**For-Life** · 06-04-2005, 08:36 PM

Originally Posted by Iakwin

Thanx for your reply

Hmmm.... so MR-10 has a lower impact resistance than poly?

but, I read from the Seiko website that their MR-10 1.67 lens are stronger than poly.

Besides Seiko, who else is using MR10 ?

Probably meant that it has a higher tensile strength.

**chip anderson** · 06-04-2005, 09:08 PM

Why does anyone care or even bother to rate tensile strength on spectacle lenses? They will never be pulled apart or subjected to any stresses that this applies to?

Chip

**Darryl Meister** · 06-04-2005, 11:07 PM

I read from the Seiko website that their MR-10 1.67 lens are stronger than poly.

In terms of straight tensile strength, as measured by those pull tests you often see, MR-10 may have a slight advantage. It's also more mechanically rigid than poly (less likely to flex against an applied force). However, poly generally shows more impact resistance -- at least in the test results I've seen. Of course, tensile strength is heavily influenced by a number of factors, including lens thickness, coatings, and so on, and both materials offer an extremely high level of tensile strength.

Why does anyone care or even bother to rate tensile strength on spectacle lenses? They will never be pulled apart or subjected to any stresses that this applies to?

Really, even an impact failure ultimately depends a great deal on the tensile strength of the material, since fractures frequently occur when the lens flexes from the impact, causing the surface to literally tear apart at the rear. However, pull-like tests generally measure tensile strength as it relates to rimless mountings.

Best regards,
Darryl

**eyeboy** · 05-30-2006, 11:18 AM

Is one of them more scratch resistant?

**HarryChiling** · 05-31-2006, 04:43 PM

Is one of them more scratch resistant?

MR 10 is more scratch resistant than poly. The added advatage is that with MR 10 you can place it in a styrofoam cup in the microwave for 15 seconds at a time and the lens will fill in light scratches when it is heated this way. Place the lens in the cup concave side down with no air trapped underneath.

**For-Life** · 05-31-2006, 05:43 PM

Originally Posted by HarryChiling

MR 10 is more scratch resistant than poly. The added advatage is that with MR 10 you can place it in a styrofoam cup in the microwave for 15 seconds at a time and the lens will fill in light scratches when it is heated this way. Place the lens in the cup concave side down with no air trapped underneath.

Would not want to try that with AR

And there really is no point in selling a 1.67 without AR

**HarryChiling** · 06-01-2006, 08:43 AM

And there really is no point in selling a 1.67 without AR

You would be suprised how many people still don't like AR. Even with the newer coatings some people are just harsher on glasses.

**For-Life** · 06-01-2006, 09:19 AM

a 1.67 without AR just makes the lenses look awful. In my opinion, a lens is more cosmetically pleasing with AR and a 1.5 index, than without and a 1.67 index.