Glasses with base 8 lenses are becoming increasingly common on our market. Originally from the world of sport, they are now an everyday fashion item.
The problem with base 8 glasses, which were originally designed as sports or sunglasses, arose when users started asking for an ophthalmic lens rather than the neutral lens, especially if negative.
IODA has created VEGA2 aspherical semi-finished products so lenses can be created with a negative and positive power suitable for wraparound frames.
To put it simply, we can say that the semi-finished product is divided into 3 zones:
-The first is the useful optical zone, where the radius is constant, the decentralization equals 7.5 mm in relation to the geometrical center of the semi-finished product.
-The connection zone, where the optical zone is connected to the base 9 zone; in this zone the radius changes constantly as the distance varies from the center of the optical zone.
-Base 9 zone, through which the lens obtained is suitable for wraparound frames.
VEGA2 semi-finished products are available in three materials: CR-39 (1.498); Rav 7/55 (1.56); MR8 (1.6)
The range of obtainable powers goes from -8.00 to + 4.00 diopters depending on the semi-finished product used: Vega2 is divided into 4 bases for the negative powers (4/9, 5/9, 6/9 and 7/9) and 2 for the positive powers (8/9 and 9/7).