|1.56 Semi Finished Progressive(14mm) Lens|
Material: 1.56 Index Resin(Ne=1.56, Abbe=38, Specific Gravity=1.28)
Add Power: +1.00 to +3.50 in 0.25D steps
|CONVEX SURFACE||CONCAVE SURFACE|
|Mominal Curve||Actual Curve|
|Nominal Base Curve||Recommended Diopter in Base||Cylinder|
|3.00||-12.00 to -4.75||0~-6.00|
|4.00||-4.50 to +2.25||0~-6.00|
|5.00||+2.25 to +5.00||0~-6.00|
|6.00||+5.25 to +7.50||0~-6.00|
Why progressive lenses?
You may be maturing, but "mature" doesn't have to mean "old." If you are in your 40s (or older) and are having trouble reading fine print with your glasses, progressive lenses offer a younger-looking appearance and other advantages over the lined bifocal lenses your parents wore.
Progressive lenses, sometimes called "no-line bifocals," eliminate the visible lines of traditional bifocals and trifocals and hide the fact that you need reading glasses.
With progressive lenses, no one has to know whether you're wearing glasses just for fashion — or because your arms have "grown too short" for you to see up close.
Generally speaking, 1.56 progressive lens has 12&14mm corridor. The gradient starts at the wearer's distance prescription, at the top of the lens and reaches a maximum addition power, or the full reading addition, at the bottom of the lens. The length of the progressive power gradient on the lens surface depends on the design of the lens, with a final addition power between 0.75 and 3.50 dioptres. The addition value prescribed depends on the level of presbyopia of the patient. In general the older the patient, the higher the addition.
How do progressive lens work?
Progressive lenses give you three vision powers in one seamless lens for a more natural and flattering way to see your world. If you need more than one lens strength to read, do computer work or drive, progressives let you see clearly at any distance with one pair of glasses. You simply adjust your head position to see three ranges of distance. Bring your head up to see far away; look straight ahead for mid-range vision, and point your nose down to read or do close-up work, like texting.