Progressive multi-focal lenses
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Sep 18, 1984
Grant Date -
N/A
app pub date -
Apr 13, 1981
filing date -
Apr 12, 1980
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A progressive multi-focal lens is provided of the type having a distant viewing zone, a near viewing zone, and a progressive zone therebetween. The surface refractive power increases vertically from an upper portion of the lens to a lower portion as the line of sight scans from a distant view to a near view. Side zones are provided beside the progressive and near viewing zones. The side zones are spheric surfaces, with a dioptric refractive power in accordance with one embodiment being the arithmetic mean value of the refractive power of the near and distant viewing zones. This eliminates astigmatism problems in the side areas and permits normal side sight.
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Advertisement
Advertisement
Advertisement
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully