Hey Guys
I'm working as distributer of Kodak lens in Egypt . and some times i face Problem with Kodak Unique HD progressive lenses from hyperopic patients. They can't adapt with it and . the strange thing that the optician changes the lenses to Varilux Comfort traditional.and " surprise"�� . customer can see without problems. Is this normal? What could be the reaons? And how to solve this peoblem ??
Welcome to OB.Originally Posted by Magid William
Full backside freeform designs put the power curve, distance and near combined, on the back surface. A +3.00 add +2.50 O.U. Rx forces a steeper base curve (to keep the back curve somewhat concave) than a front aspheric PAL, one where the add is on the front and the distance on the back. The steeper bass increases the sag depth, increasing magnification, and tends to look bulbous, not a good direction for what might be considered a more advanced lens.
Moreover, to minimize the above effects, a high index lens is usually used, which increases Chromatic Aberration and expense. Consider lenses that have the add split on both surfaces, use a "Camber" type lens, and/or medium index of refraction lenses (1.60) to minimized CA.
There's a forum dedicated to progressive lenses.
Hope this helps,
Robert Martellaro
Science is a way of trying not to fool yourself. - Richard P. Feynman
Experience is the hardest teacher. She gives the test before the lesson.
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