The new Hydron Echelon contact lens is a soft bifocal wich incorporates a diffractive phase plate on its back surface. This phase plate, which divides the incoming light into equal near and distance foci, utilizes the entire surface of the optic zone and is therefore not dependent on translation or pupil size. The lens gives greater resolution of image and less of a secondary blurred image. In this small study of 24 well-motivated presbyopic patients, 60% were able to wear the lens successfully. Patient selection and lens centration are critical. Adaptation generally takes 6-12 weeks, but most optical side effects are transient. The main disadvantages are reduced contrast sensitivity at near and a ghosting of images. This lens thus appears to to represent a significant advencement in soft bifocal contact lens fitting.
|Translated title of the contribution||Echelon - Diffractive soft bifocal lens for presbyopia|
|Number of pages||4|
|State||Published - Jan 1 1990|
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