What lenses should I get?

[Sponges]

Looking for advice. I'm thinking about ordering some rimless glasses
from zenni. I have a pretty mild prescription, -2.25 in both eyes.
Should I get the mid-index lenses (1.56) or would going for a higher
index (1.61 or 1.67) be worth the expense? Thanks!

[Chuck Knight]

I'm not sure Zenni *would* fill your prescription in high index -- with rimless glasses, there is a structural requirement that the lenses be of a certain thickness, and they'd be wafer thin if they made them in high index plastic.

You might call and ask, though.

     -- Chuck Knight

--~--~---------~--~----~------------~-------~--~----~

[IMQ]

You would be absolutely fine with 1.56 lens (or 1.57, according to
Zenni). It would be a big waste of money to go higher since there's
barely a difference between 1.56 and higher index lenses. I know
because I have both Zenni standard 1.57 and Optical4Less 1.67, and my
Rx are -2.50 for both eyes. Your lenses would be negligibly thinner
(by a hair, if that). In fact all my glasses from Zenni have the Zenni
standard 1.57 lens.

The reason only reason I had 1.67 from O4L because I never had hi-
index and I was curious to see the difference.

Keep in mine too that the higher the index, the lower the Abbe value
the lens will have. Higher Abbe value lenses have better optical
quality.

Here is the page that calculate the lens thickness based on Rx and
frame size:

http://opticampus.com/tools/thickness.php

Remember the size of your frame, all things being equal, determine how
thick the edge will be. Smaller frames have thinner edge, so pick the
smallest frame you can comfortably wear. When I say frame size, I mean
the eye size of your frame. If you look at the frames online, you
typically see numbers in this format:

Eye size -- Nose bridge -- Temple

For example, one of my frames from Zenni is 52-18-140. I have 2
rimless frames from Zenni (#3258) and the lenses are just a little
thicker than 2mm at the edges. Basically a little thicker than the
thickness (anout 2mm) of typical metal frames.

As an added bonus, Zenni also polish the edges, making the lenses
appear even thinner!

Hope this help.

[Paul]

I got a 1.56 lens from Zenni in a rimless frame with 46 mm lenses. The
prescription was high, -5.75 in both eyes. The edge looks perfectly
fine, especially since it's polished.

With a -2.25 prescription, even CR-39 plastic (index 1.50) would look
quite thin, even in a somewhat large frame.

[mzdtk]

get the regular lense the rimless needs to be thicker because the
frame is attached to the lenses and therefore will tolerate the stress
that this frame puts on the lenses

On May 30, 10:10�am, Sponges <iamthespo...@yahoo.com> wrote:

[Hal]

Paul - I have a -6.0 script for my right eye, but I'm worried about
the thickness of the lens with mid-index. How thick is yours at -5.75?
The opticalcampus.com site above put me at close to 1cm with 1.67 high
index, which seems way too thick.

[Chuck Knight]

Minus prescriptions are thicker at the edges, and get thicker as the lenses get bigger.

You could always select a smaller lens...and the rounder the better.  That should minimize the lens thickness as much as possible.

     -- Chuck Knight

[Hal]

Chuck - thanks for the response. What do you mean by 'the rounder the
better'? I'm looking at something about 48mm wide, and 30mm tall at
the most, but not rounded e.g. http://zennioptical.com/cart/product.php?productid=705&cat=10&page=1

Does that seem suitable for a script of my strength?

> > index, which seems way too thick.- Hide quoted text -
>
> - Show quoted text -

[Paul]

To give a couple of real-life examples, I have two pairs of glasses
with -6.00 prescriptions. The one from Zenni is 46 mm wide X 32 mm
high and has their standard 1.57 polycarbonate. The lens is 5 mm thick
at the end, and 3 mm wide at the top and bottom. The other one is
round - about 44 mm X 44 mm - and is made from CR-39. It's also 5 mm
thick at the edge.

[Hal]

I greatly appreciate your fast feedback, especially the examples.
Right now I have a pair of 7-yr old glasses that are 46mm x 30mm, and
about 5mm thick at the edge, and I'd hate to get much thicker - my
other eye is actually -3.75, and the varying lens sizes make the
glasses awkward at anything thicker. I'm enjoying the prospect of
getting a new pair, almost a decade later, for a fifth of the price
of my current ones.

[Paul]

The lenses look less thick if they're polished at the edges.