Why do thinner lenses make sense?
Thinner lenses increase wear comfort for nearsighted wearers with a prescription from –3.00 and farsighted wearers with a prescription from +2.00.
Lens thickness can be reduced by increasing the refractive index, which can be selected based on the expected strength of the prescription.
The refractive index is 1.5 for normal lenses and approximately 1.6 for thinner lenses. The index of extra-thin lenses is over 1.67 for organic materials and over 1.7 for mineral lenses. When it comes to ultra-thin lenses, this figure is 1.74 for organic lenses and between 1.7 and 1.8 for mineral materials.