ON LINE TRAINING
SUNLENSES
The base of a lens
The type of base, usually between 2 and 8 in sun lenses, is an important measurement to order an eyewear lens. The higher the value of the base of the lens, the higher is the curve of the lens, therefore matching the higher front curve of the frame.
Base 2
Base 4 Base 6 Base 8 For fashion frames with straighter fronts For “trendy” frames like many of the latest 
generation frames For traditional frames for sport wrap around frames.
The lens has a spherical shift as: Polycarbonate decentralized lenses with 20 – 24 mm CR39 decentralized lenses: with 15 – 18 mm
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a = inclination of the front
PC: shift and with an inclination of the front from
15° to 25° CR39: shift and with an inclination of the front up to 15°
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The basis
Coatings
Materials and thicknesses
Categories
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