1.74 Index Lens for Semi-rimless Frame

by Tu
(Santa Clara)

Q: Hi,

Can 1.74 index be used on semi-rimless frame?
I was told by the local provider that 1.74 cannot be used for semi-rimless frame, has to go to 1.67. is it true or not?

A: Hello

Well, the answer is more complicated than this...

It depends on the diopters of the lens and how big is the frame.

There is a minimum thickness that the lens must have for mounting in the semi-rimless frame.

The 1.74 index lenses are indeed thinner. If you add this to (+) diopters (they are thinner at the edges), you got an extra thin lens that you cannot mount in the semi-rimless frame.

In this case, I recommend you a smaller frame, because the lens is thicker at the center.

If your diopters are (-), then the lens is thinner at the center, so a 1.74 lens is even thinner, but get thicker at the edge, so if this is your situation, I recommend a bigger frame, this way maybe it will meet the minimum thickness.

All this if you insist having the 1.74. If this is not possible, then I think the 1.67 is not a bad option.

Hope this helps,
Arpi

Comments for 1.74 Index Lens for Semi-rimless Frame

Click here to add your own comments

Apr 21, 2018

Semirimless with Prisms - which Index lense should I get?
by: hammie time

I need to get driving glasses that have no distance RX (since I wear contacts) and have just a prism Rx (5.0 HBase Out). They don't have my frame size in the full frame but have a semi-rimless. I was thinking of doing the 1.6 or 1.67 index. Is that OK to do with prisms?

May 02, 2018

Answer - Semirimless with Prisms
by: Arpi

Normally it is ok, the prism, like the diopters, can be made thinner, but 5.
Prism it is pretty big, so with the 1.67 the lense will be still thicker , but it helps.
I think 1.67 with semi-rimless it is a good idea , but more expensive.

Click here to add your own comments

Join in and write your own page! It's easy to do. How? Simply click here to return to FAQ.