by admin | Jan 25, 2010 | Lens Form and Theory
Industry studies have shown that approximately 70% of all spectacle wearers receive a cylinder correction for astigmatism. Further, 50% of these wearers have corrections with over 0.50 D of cylinder power. This article will show that conventional lens design does not...
by admin | Jan 25, 2010 | Lens Form and Theory
A progressive addition lens (PAL) is a type of multifocal lens that employs a surface with a continuously smooth increase in addition (Plus) power. The curvature of the surface increases from its minimum value in the distance zone to its maximum value in the near zone...
by admin | May 5, 1010 | Lens Form and Theory
Download the printable resultant prism chart, handy for converting the two-component prescriber's method of specifying prism to a single component resultant method. Resultant Prism Chart
