The requirements for spectacle lenses are manifold. Above all, they should have the following characteristics, so that the wearer of lenses can enjoy them as long as possible:
- Brilliant optical imaging features
- Chemical and thermal resistance
- High light transmission
- Low reflection
- Mechanical robustness
Which materials are available?
Basically, customers can choose between two lens materials: mineral glass or organic.
The optical properties of both materials are very good.
Mineral glass has been the traditional material for spectacle lenses for centuries. The material consists, similar to a conventional glass, of a special combination of quartz, soda and lime.
It is more environmentally friendly than organic because it works without synthetic additives and pollutes less the environment due to its recyclability. Compared to organic it breaks more easily and is a bit heavier but shows robustness and scratch resistance. Mineral lenses have lost none of their relevance to many professions (such as craftsmen).
OPHTHALMICA has a large selection of mineral lenses and offers these in the indices 1.5 - 1.9.
Plastic lenses (also called organic) have found their way into the lens industry since the 1940s.
They are lighter and break less easily than mineral lenses. Plastic lenses can usually be tinted very well (exception: Trivex 1.53) and can be used in sunglasses as photochromic or polarised lenses.
Higher-index organic materials (Index 1.6 and 1.67) are ideal for nylor and drilling lenses because the material is less brittle.
OPHTHALMICA offers organic lenses in the indices 1.5, 1.53, 1.6, 1.67 as well as the high-index world's thinnest 1.76 lens.
This very shatter-proof and lightweight material offers a good image quality with a low specific weight of 1.12 g / cm3. Its stability and lightness are therefore well suited for rimless frames, sports and children lenses. However, the Trivex material is not suitable for tinting.
- Deep Blue Deep Blue UV 420 material (based on MR8) provides good protection of the eyes from harmful radiation up to and including 420nm wavelength with the help of a new additive in the plastic / polymer of the glass
- The blue effect is "in the material" - no coating as with other glasses (BV anti-reflection)