up a lens?
A lens is made up of three components:
Material - The look, weight and resistance of your glasses will depend on whether the lens is made from plastic, polycarbonate, high-index plastic or glass.
Lens technology - This is applied on either or both sides of the lens to enhance the features of the design and material. It can extend the longevity of glasses and improve clarity of vision. Options include photochromic, polarised, anti-reflective, anti-scratch and anti-smudge, and coatings that repel dust or water and combat fog.