Question

which is high refraction index lens.
option a) bifocal lens
option b) progressive lens option c) lenticular lens
option d) none of these​

Answer 1

Answer:

A lens is high-index when the refractive index exceeds that of plastic or glass. There are numerous refractive indices of high-index lenses. The general range is about 1.53 to 1.74. When the refractive index is 1.70 or more, the lens is generally at least 50 percent thinner compared to a conventional plastic lens.