What is the index of refraction of CR-39?

In the case of CR-39 plastics, the Refractive Index is 1.49, meaning that light travels at almost half the speed through it than it does through a vacuum. The range of the Refractive indices of different lens materials ranges from 1.49 to 1.74. The higher this number, the slower the light moves through it.

What is the difference between CR-39 and polycarbonate lenses?

Polycarbonate lenses have a higher index of refraction (1.586) than CR-39 plastic (1.498) and are therefore thinner in an equal lens prescription. With a higher index (of refraction), light is bent more efficiently, therefore it requires less material to achieve the eyeglass prescription making the lenses much lighter.

Is CR-39 plastic or glass?

The first lightweight plastic eyeglass lenses were made of a plastic polymer called CR-39, and this kind of plastic is still a popular option for lenses today.

Are CR-39 lenses good?

It’s optical quality is almost as good as glass (and far better than all the other options we will look at), it is half as heavy as glass, it is much more resistant to shattering, and still very resistant to scratches. In ‘raw’ form, before cut to your frames – CR-39 lenses.

What is the refractive index of water?

Refractive Index Formula

Material Refractive Index
Air 1.0003
Water 1.333
Diamond 2.417
Ice 1.31

Do CR-39 lenses have UV protection?

Conclusions: These data suggest that UV tinted CR-39 lenses provide protection against UV radiation that meets the ANSI Z80. 3-1996 Standard for non-prescription sunglasses and fashion eyewear.

Does CR-39 block UV?

Are CR-39 lenses polarized?

CR39 polarized lenses are the most popular plastic resin sunglass lenses in the world. CR39 resin makes high quality polarized sunglass lenses and also has a cost and weight advantage over glass.

Is CR-39 UV resistant?

CR-39 does in fact block UV light, but only up to 360nm. I believe the big reason that CR-39 does not block up to 400nm by itself is the UV filter at that point would cause the lens to be tinted light yellow, which is cosmetically unappealing. CR39 used to go yellow in the 1970’s because of UV influence.

Is CR-39 clearer than polycarbonate?

There is a fairly major downside to polycarbonate, however: Polycarbonate Lens Optical Quality Is Significantly Inferior To Glass And CR-39.

What is the refractive index of water to glass?

The refractive index of light entering glass from water is 1.12.

What is the refractive index of glass with respect to water?

Refractive index of glass with respect to air is (3/2) .