Gresset J
Ecole d'Optometrie, Universite de Montreal, Quebec, Canada.
J Am Optom Assoc. 1991 Sep;62(9):691-8.
Throughout the first quarter of 1989, 14 professionals field-tested Varilux Infinity prior to its launching. The study was conducted to determine the following factors: the level of ability to adapt, length of the adaptation process, ratings of distortion and head movements, and level of satisfaction. Varilux Infinity was systematically offered to each potential user whatever the prescription requirement. Among the 720 persons who were fitted in the course of the experiment, only 8 (1.1 percent) could not adapt. After a 6-week trial period, 168 answered a survey as to their level of satisfaction with the new progressive lenses. The results show that the parameters of the prescription (ametropia, cylinder, axis, addition) are not related to either the length of the adaptation process or the other ratings of the Multi-Design progressive lens. Experienced wearers of progressive lenses adapt more quickly and are the most favorable in their evaluation of the new lens. On the other hand, first-time users of progressive lenses offer the same response as did new wearers of Varilux 2. However, wearers of Varilux Infinity do not notice as much the need for head movements. This improvement can be considered as a point in favor of the wider visual field provided by Varilux Infinity. On the whole, the most active and the least active patients respond similarly in their evaluation of the new lens. The ametropia, add power, or level of activity cannot be held as risk factors in the adaptation to Varilux Infinity.