1) It’s inexpensive, since it’s been around for over 70 years. Optically speaking, it has a good, reasonably smooth refractive surface, and very little distortion at the edges of the lens
2) The big advantages of CR39 lenses over previous glass lenses were light weight, and better shatter resistance. The lower weight allowed eyeglass makers to experiment with larger size lenses, since CR39 is much lighter in weight.
3) Although CR39 has better shatter resistance than glass lenses, it still can shatter under a strong impact. For this reason, more and more optical professionals are moving to newer lens materials (polycarbonate and others, to be discussed in future posts) that are almost impossible to shatter.
| || ------Natural, clear and balanced vision from far to near |
------Low astigmatism provides visual comfort and easy adaptation
------Larger far zone and comfortable reading zone
Multifocal lens is a lens with which one can see clearly and smoothly at all distances with comfort. The spectacles look more aesthetic and afford an unimpeded view to the eyes.