| 摘要 |
PROBLEM TO BE SOLVED: To provide extremely thin plastic lenses for correcting far sight or presbyotic eye refraction. SOLUTION: Various kinds of the plastic lenses of a single focus, multifocuses and progressive refracting power formed with lens shapes of convex specifications of both-side spherical surfaces or aspherical surfaces are provided. K=K1 +K2 holds with the refracting power K of the lens when the refracting power of the first face (objective face) is defined as K1 and the refracting power of the second face (the surface facing the eye) as K2 and therefore if both of the first face and the second face are formed of convex specifications, the refracting power of the respective surfaces acts positive and therefore the central thickness can be made thinner since the refracting power of the lens increases. Further preferably, both surfaces are formed to aspherical shapes, by which the thickness of the lens can be reduced and consequently, the lightweight lens having extremely decreased aberrations can be provided.
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