Aspheric lenses are designed to be thinner and flatter than traditional lenses whilst optimised both cosmetically and optically. Also, normal lenses have a convex shape, which can slightly distort your eyes, whereas aspheric lenses being thinner and flatter, do not distort your image. These lenses find exceptional clarity in a wider field of natural vision enhancing both wearer comfort and optical performance.
You can purchase these lenses as both varifocal, and single vision lenses. If you have a higher prescription than normal, you are still able to wear the thinnest lenses. They are available as a 1.8 varifocal lens and a 1.9 single vision lens.
1.8 Index GlassThin Lens (Varifocal Only)
Only available in varifocal for highest +/- prescriptions. This is the thinnest material for a varifocal, however it is around 2 times heavier than both the 1.67 lens and the 1.74 lens index in plastic. Unless you have aminus prescription of between 15 and 20, it is always recommended that you have a 1.76 indexlens instead due to the weight disadvantage. This lens can only be applied with an anti-reflective coating as an additional extra.
1.9 Index GlassThin Lens (Single Vision Only) The thinnest lens material available for very high prescriptions and should really only be used on the highest type of prescriptions, for example +10 or -17 sphere as the weight disadvantage makes it impractical on lower prescriptions where 1.74 thin lensor 1.76 thin lens plastic would be more suitable. This lens can only be applied with an anti-reflective coating as an additional extra.