渐进片验配（Progressive piece fitting）.docVIP

渐进片验配（Progressive piece fitting） Since 1959, the multi focus lens has been developed and improved continuously for nearly half a century, and has formed two design trends: soft and rigid. The main difference between the two designs is the length of the progressive channel. Rigid design progressive piece progressive channel short, around the aberration is relatively small, in order to ensure the visual distance, vertical dimension less demand, such as youth progressive belongs to the design, but because of the short channel gradient, so the gradual process is too fast, the design than older people, more difficult to adapt to the gradual progressive film channel; the soft design is relatively long, around the aberration is relatively large, but because of the gradual channel long, gradual process is quite gentle, easy to let the wearer to become the market mainstream progressive film sales. In recent years, with the continuous development of glasses technology, and the improvement of peoples living standard and quality, progressive multifocal lenses are more and more popular among young people and middle-aged and elderly ametropia customers. However, due to the technical limitations of optometry, peoples understanding and the penetration rate is still very low, the progressive multifocal lens fitting is introduced. The design principle and characteristics of progressive multifocal lenses The progressive multifocal lens is designed to produce a continuous, near, near vision on a lens. The feature is shown in Fig. 1. The upper part is used for far diopter, the lower part of the lens is near diopter, and the center of the lens is a region of gradual change of diopter. Most of the progressive lenses were near the zone, the optical center in the far zone, the optical center under 10-16mm, and the nasal side 2-2.5mm. Both sides of the progressive region are aberrations, and when the line of sight moves toward this region, the deformation of the object is observed, and the e