Mineral lenses (glass)

Recommendations

* Standard eyeglass lenses made of material with a refractive index of 1.52 are recommended for low ametropia: Sph from - 3.0 to +2.0 D.

* Spectacle lenses made from a material with a refractive index of 1.6 are 22 percent thinner than standard spectacle lenses and are recommended for low to moderate ametropia: Sph from - 1.0 to - 5.0 D and Sph from + 1.0 to +3.0 D.

* Spectacle lenses made from a material with a refractive index of 1.7 are 30 percent thinner than standard spectacle lenses and are recommended for Sph from - 4.0 to - 8.0 D and Sph from +2.0 to +4 , 0 D.

* Spectacle lenses made of material with a refractive index of 1.8 are 40 percent thinner than standard spectacle lenses and are recommended for high myopia: Sph from - 6.0 to - 12.0 D.

* Spectacle lenses made of a material with a refractive index of 1.9 are 50 percent thinner than standard spectacle lenses and are recommended for high myopia: Sph from - 8.0 to - 16.0 D.

* Lenticular spectacle lenses are recommended in cases of high myopia: Sph from - 14.0 to - 30.0 D.

* Spectacle lenses with an aspherical surface design are recommended for moderate to high hyperopia: Sph from +2.25 to +8.0 D.

* To increase the light transmission of spectacle lenses, reduce reflections, and therefore reduce eye fatigue, anti-reflective coatings should be recommended. For spectacle lenses with a high refractive index, this is a must.

* The smaller the aperture of the rim of the frame, the smaller the edge thickness of the negative refractive spectacle lenses and the lighter the finished glasses.

* The higher the refractive index, the smaller the edge thickness for spectacle lenses with negative refractions (see the figure below "Spectacle lens thickness versus refractive index).

* The smaller the diameter of the ordered spectacle lenses of positive refractions, the thinner they are in the center and the lighter the finished glasses.

* In special cases, when spectacle lenses with parameters different from standard ones are required, you can use additional services for their production, which are offered by leading foreign manufacturers of spectacle lenses and some domestic laboratories.