Bifocal is a presbyopic solution with a vision field for distance in the upper part and a near vision field in the lower part of the lens. The near vision field or the so-called segment can be available in two variants, such as the transition line of the segment - straight FT (Flat Top) and curved CT (Curve Top) as well as the width of the segment expressed in millimeters 28, 35, 45, and along the entire of the lower part of the lens.
Two zones of use (distance and proximity)
Flat segment FT-28, FT-35, FT-45
Curved segment CT-28
E-Line segment (Executive bifocal)
Traditional technology
