公开(公告)号：JPH02157811A

公开(公告)日：1990-06-18

申请号：JP27360389

申请日：1989-10-20

Applicant: ESSILOR INT

Inventor： DANIERU KORUNU ,  KURISUCHIYAN ARUSHIINI ,  JIYAN TEIEEBOO

IPC: G02C7/04 ,  G02C7/02

Abstract: PURPOSE: To provide a relatively light-weight ophthalmologic lens with a large diameter having a positive refractive power by making the diameter of a central optical working area almost equal to the diameter of the geometrical outline of the lens, and having a special relation with the refractive power. CONSTITUTION: A diameter D1 of the central optical working area 10 of a lens is made almost equal to a diameter D2 of a geometrical outline 11. Then, a peripheral blending area 12 is provided between the optical working area and the geometrical outline 11 in the surrounding of the optical working area. In this case, a diameter D1 mm and a refractive power P diopter are related with each other in order to fulfill an expression D1 =a.b.P. Here, the values of a=84-89, and b=4-9 are used. Thus, the positive reflective power P=2-9 can be attained, and the relatively light opthalomological lens with a large diameter can be obtained.