28-04-2016 дата публикации
Номер: US20160116763A1
The present invention is directed to a method for designing a soft contact lens with semi-customized back surface including determining axial radius topography data for a plurality of eyes of a specific population; calculating an apical radius and a conic constant distribution from the axial radius data; determining apical radius and conic constant values for an individual subject; selecting a subset of base curves from a base curve library based on the individual subject's apical radius and conic constant values; and selecting a final base curve from the subset of base curves that fits the individual subject's needs based on one or more selection criteria. 1. A method for designing a soft contact lens with a semi-customized back surface , comprising:determining axial radius data for a plurality of eyes of a specific population;fitting the axial radius data using equations that define an aspheric surface as a change in axial radius for an apical radius and a conic constant;determining apical radius and conic constant values for an individual subject;selecting a subset of base curves from a base curve library based on the individual subject's apical radius and conic constant values; andselecting a final base curve from said subset of base curves that fits the individual subject's needs based on one or more selection criteria.2. The method according to claim 1 , wherein said axial radius data for the specific population are measured or calculated from corneal topography data.3. The method according to claim 1 , wherein said fitting comprises calculating an apical radius Rand a conic constant k using the following Equations (1a) and (1b):{'br': None, 'i': R', '=R', 'p', 'y, 'sub': S', '0, 'sup': 2', '2', '2, '+(1−)·\u2003\u2003(1a)'}{'br': None, 'i': R', '=R', 'k', 'y, 'sub': S', '0, 'sup': 2', '2', '2, '+(−)·\u2003\u2003(1b)'}{'sub': 0', 'S, 'wherein Ris the apical radius, Ris the axial radius at a distance y from the corneal apex, and p is a rate of change of the ...
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