Progressive power lens

A progressive power eyeglass lens is disclosed. The lens is particularly suitable for close-range work while facilitating distinct vision up to a specific distance that is substantially separated from the close-view distance. The lens also provides a wide distinct-vision area in the near-vision regi...

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Hauptverfasser: UMEDA, TOSHIAKI
Format: Patent
Sprache:eng
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Beschreibung
Zusammenfassung:A progressive power eyeglass lens is disclosed. The lens is particularly suitable for close-range work while facilitating distinct vision up to a specific distance that is substantially separated from the close-view distance. The lens also provides a wide distinct-vision area in the near-vision region. The lens comprises a near-vision correction region with a surface refractive power suitable for near vision, a specific-distance-vision correction region with a surface refractive power suitable for a specific distance that is substantially separated from the close-view distance, and a progressive zone between the near-vision correction region and the specific-distance-vision correction region that provides a gradual change in refractive index from the near-vision correction region to the specific-distance-vision correction region. The length of the progressive zone from the center of the specific-distance-vision correction region to the center of the near-vision correction region is at least 15 mm, and the minimum width of the distinct-vision area in the near-vision correction region is at least 5 times the minimum width of the distinct-vision area in the progressive zone.