Lenses
Thickness
The index of refraction
The higher the refractive index, the thinner, lighter and more attractive the lens at
the same dioptre value. This not only increases comfort, but also makes them look good.
The advantage of thin lenses is that you are relatively free in your choice of
frame.
The lenses are also more comfortable to wear due to the reduced weight. Spectacle
wearers with high values should therefore always opt for a higher index. Click on
“spectacle advice” to find out more about the various characteristics of the
indices.
Which materials can be used for lenses?
Although we usually refer to
the spectacles we wear as “glasses”, we don’t realise that most lenses are now made of
plastic. In principle, opticians have the option of choosing between mineral glass or
plastic. These two materials have different properties that play an important role in
the purchase decision.
Mineral glass is the traditional material for spectacle lenses. Like conventional glass,
it consists of a special mixture of quartz, soda and lime. It breaks more easily and is
heavier than plastic. The advantages: it is robust and scratches less easily. Protection
against scratches is now achieved by special coatings, even on plastic lenses. That’s
why about 95% of all spectacle wearers choose plastic lenses.
Which materials can be used for lenses?
Although we usually refer to
the spectacles we wear as “glasses”, we don’t realise that most lenses are now made of
plastic. In principle, opticians have the option of choosing between mineral glass or
plastic. These two materials have different properties that play an important role in
the purchase decision.
Mineral glass is the traditional material for spectacle lenses. Like conventional glass,
it consists of a special mixture of quartz, soda and lime. It breaks more easily and is
heavier than plastic. The advantages: it is robust and scratches less easily. Protection
against scratches is now achieved by special coatings, even on plastic lenses. That’s
why about 95% of all spectacle wearers choose plastic lenses.