1.61 vs 1.67 rimless frames

[Nub]

I'm trying to decide what material to use.
I'm looking at this rimless frame. http://zennioptical.com/cart/product.php?productid=968
The lens is 53 x 33

My script is as follows.
-3.75 -2.50 4
-4.00 -1.75 179

Would there be a noticeable difference between the two materials for
my script?

[Chalo]

Those are wide lenses (in your chosen frames). Higher index material
will be noticeably thinner at the outer edge. However, I would base
my decision on whichever material is stronger. Rimless framed glasses
are depressingly weak, and weak lens material gives them more ways to
fail.

Chalo

[Tripp South]

I ordered some semi-rimless from Zenni a couple of years ago and chose
the 1.61,high-index lenses at check out. The next day I got a call
from Zenni customer service, asking if I had intentionally picked the
thinner lenses or had I made a mistake. The lady on the phone was so
nice. She explained the differences between the three options and
told me that with my prescription [-1.25/-1.25 -.50/-.50 90/105] I
would be wasting my money

It seems the higher index lenses help "compact" a stronger
prescription into a thinner package. The way she explained it to me,
there were ranges of prescriptions that were suitable for the 1.57,
1.61 and 1.67 high-index lens options; the stronger the prescription
the higher the index.

I'm not optomistrist, but your prescription doesn't sound that strong
to me. I'd think that you’d be just as well served by the 1.61 index
option as the 1.67. If you could find a place to sell you the highest
index lenses you probably couldn't tell the difference between 1.67
and 1.61 in your, weaker Rx.

I bet you've already read it, but for future reference here's Zenni's
Lens/Materials webpage:

http://www.zennioptical.com/cart/pages.php?pageid=8

[shell]

I think I remember someone saying that Zenni will only use their Thin
and Light 1.57 index lens on prescriptions -5.00 and weaker. I think
that the higher index lenses you're interested in are only available
for stronger prescriptions. That said, here's lens thickness
calculator: http://www.opticampus.com/tools/thickness.php

[Paul]

I've only used Zenni's 1.57 lenses, with prescriptions up to -6.50. I
never got any warnings or calls from them about it. With smaller
lenses, the thickness isn't a problem.