How thick is the 1.67700-degree lens?

1.67 refraction of 700 degrees should have a thickness of 7-8㎜.

Generally speaking, 700 degrees is the degree of the lens, and 1.67 is the refractive index of the lens. Generally, the thickness of lenses with this degree and refraction is about 7-8 mm, and 700 degrees is a high myopia lens, so its thickness will increase accordingly, and the lenses are also made of different materials. At present, the commonly used myopia lens materials are glass, resin and PC lens.

For 700-degree myopia glasses, the lens thickness of 1.67 refractive index is also related to your personal pupillary distance and the size of the frame you choose. If you want to make the glasses thin, you'd better choose the frame of TR90.

The higher the refractive index of lens material, the stronger the ability to refract incident light. The higher the refractive index, the thinner the lens thickness, that is, the same lens center thickness, the same degree of the same material, the higher the refractive index is thinner than the lens edge with low refractive index. That is to say, lenses with the same diopter and the same diameter have thinner edges with refractive index of 1.7 1 than those with refractive index of 1.67, and are more beautiful to wear.

for instance

A lens with a myopia of 800 degrees and a diameter of 60mm, 1.67 lens thickness is 6.7mm, 1.74 lens thickness is 6.1mm. ..

A lens with a myopia of 300 degrees and a diameter of 60mm, the thickness of 1.67 lens is 3.2mm, and the thickness of 1.74 lens is 2.9 mm ..