"which is the thinnest lense for eyeglasses,hyper index or poly tegea?pls. reply.thanks"?

Answer 1

The thinnest lens that I have worked with is the hyper index 1.71. There are different index lenses such as the mid-index 1.56, hi index 1.60, hyper index 1.66 and hyper index 1.71. The poly tegra is really thin but I have heard more complaints about the distortion in the poly tegra then the hyper index 1.71. If you are under 18, though, most opticals and optometrists will not let you get the hyper index for safety reasons (they can get sued for not selling the poly). Poly lenses are shatter resistant while the hyper index is not.

Edited to add....I do not support any type of glass lens what so ever. The other poster is talking about glass hi index lenses and here in the U.S. (not sure if the other poster lives here) most opticals only sell plastic, hi index, or polycarbonate lenses unless otherwise requested by a patient. In my opinion, even when the lens is hardened, glass is very dangerous and heavy.

Answer 2

I support Jennie B in that the high index Poly lenses do have some record of problems, if not treated with respect in manufacture and use.

1.7 is not the limit in glass lenses, (and the higher the index, the thinner the lens)
I wear 1.9 Lantal from Zeiss in my single vision glasses and 1.8 in my varifocals because they don't make them in 1.9.

Is your Rx high + or high -? For technical reasons the high-index glass lenses are not quite so suitable in the high plus form.
Glass lenses, of course, are not recommended for sport and similar activities. (but plastic lenses are not substitutes for safety glasses, for activities where they are needed)

With a high Rx, remember that the choice of frame shape and size can outweigh any savings made by a better lens material.
The smallest, roundest lens shape *that suits you* will give the best final result. Large and square lenses exaggerate the thickness that comes from the strength of the prescription.