Essilor International Cie Generale D'optique

Essilor International (compagnie Generale D'optique)

Pierre Monteil

Dominique Baude

Nicolas Chateau

Gerard Obrecht

Christian Miege

A progressive simultaneous vision optical lens for correcting presbyopia corresponding to a low addition is of the kind in which the curve representing the proximity (or power) P lies in an area between a lower envelope curve P.sub.inf and an upper envelope curve P.sub.sup having the following polynomial equations: ##EQU1## where h is the height relative to the axis of the optical lens, i.e. the radial distance from the latter. By appropriate choice of the coefficients A'.sub.i and A'.sub.i, the near vision area is made relatively large. Applications include contact lenses, intraocular implants and intracorneal lenses.

Progressive simultaneous vision optical lens for correcting presbyopia

To define a far vision area and a near vision area in a simultaneous vision ophthalmic lens for correcting presbyopia, the curve representing the proximity as a function of the distance from the axis lies within an area between a lower envelope curve and an upper envelope curve with associated specific polynomial equations in which the coefficients depend on the proximity addition corresponding to the degree of presbyopia of the wearer. Either the far vision area or the near vision area is strengthened relative to the other, the corresponding surface areas S.sub.VL, S.sub.VP being related as follows:

Simultaneous vision ophthalmic lens for correcting presbyopia and pair

The proximity P of a simultaneous vision optical lens for correcting presbyopia is defined as the reciprocal of the distance D at which a light ray parallel to and at a distance h from its axis crosses the axis after passing through the lens. The curve representing the proximity P of the lens lies between a lower envelope curve P.sub.inf and an upper envelope curve P.sub.sup satisfying the following equations:

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Paris, France

Pierre Monteil