Glass, Polycarbonate, CR-39, Trivex, 1.60... So many lenses, so little time! Do you ever find yourself overwhelmed by the amount of lens material options available on today's market?
In an analysis of prescriptions received by the laboratory, as many as 46 percent of the cylinder prescription distribution is equal to or more than 0.75 diopters (Fig. 4).
The opportunities for single-vision aspheric lenses are relatively well known. Aspheric lenses improve the cosmetics of a pair of glasses by using surface curves that are flatter centrally and progressively flattened (in plus prescriptions) as one moves from lens center to edge.
In contemporary frames, we have new challenges. First, smaller frames tend to be “flatter”. in larger frames, lenses often bulge out the front especially in plus powers.
