Progressive Varifocal Vision Semi Finished Lens Blanks Multifocal Uncoated 1.499 Index

Progressive lenses, sometimes called "no-line bifocals," give you a more youthful appearance by eliminating the visible lines found in bifocal (and trifocal) lenses.

But beyond being just a multifocal lens with no visible lines, progressive lenses offer other advantages as well: primarily, the ability to see at all distances, including at arm's length for computer use and up close for reading.

Superior F(Clear Far Vision) Ideal for you who use glasses for outdoor work. Ensures a comfortable field of vision throughout the entire distance field of vision. Additionally, aberrations are suppressed even with short progressive power corridors.   Superior B(Outstanding Balance) Balanced setting of far, intermediate and near vision. Ideal for most lifestyles and first time progressive wearers.   Superior N(Comfortable Near Vision) Widened near distance segment greatly expands the near field of view and increases wearer comfort. Recommended for you who occupy an indoor/office environment.

• Advantages of progressive lens:

1. The additional lens power required for clear vision at different viewing distances is accounted for by the natural position of the eye during the majority of day to day tasks, and can be further adjusted by tilting the head to sight through the appropriate part of the vertical progression;

2. The lens location of the correct addition power for the viewing distance usually only requires small adjustments to head position, because near vision tasks such as reading are usually low in the visual field and distant objects higher in the visual field.

3. Progressive addition lenses avoid the discontinuities (image-jumps) in the visual field created by the majority of bifocal and trifocal lenses and are more cosmetically attractive. Because bifocal and related designs are associated with 'old age', proponents have suggested the lack of segments on the lens surface of a progressive lens appears more 'youthful' because the single vision lenses associated with younger wearers are free of segments or lines on the surface.

4. Progressive lenses can use the optimization principle, which is based on linearization and represents the lens surface using spline functions. The lens’ power progressively increases between the low-power and high-power region of the lens. This specialized lens surface provides an accurate power distribution for both near and distant vision and reduces the number of optical aberrations.