Simultaneous vision optical lens for correcting presbyopia

Claim 1

Progressive simultaneous vision optical lens for correcting presbyopia in which the curve representing its proximity P defined as the reciprocal in diopters 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 lies within an area between a lower envelope curve P inf and an upper envelope curve P sup defined by nth and hth degree polynomials and satisfying the following equations: P.sub.inf =f(h) =(ΣA'.sub.i h.sup.i)+P.sub.VL P.sub.sup =f(h)=(ΣA".sub.i h.sup.i)+P.sub.VL (I) in which P VL is the proximity needed for far vision and A' i , A" i are the coefficients of the various polynomials depending on the value of the proximity addition δ 1 =A DD corresponding to the degree of presbyopia of the wearer, the values of these coefficients being substantially as follows: ______________________________________ for A.sub.DD = 1.5 D: A'0 = 12.532267 A"0 = 16.9452 A'1 = -92.695892 A"1 = -106.8394 A'2 = 305.16919 A"2 = 302.62347 A'3 = -513.44922 A"3 = -443.97601 A'4 = 476.63852 A"4 = 362.53815 A'5 = -247.99097 A"5 = -166.29979 A'6 = 67.868942 A"6 = 40.015385 A'7 = -7.6131396 A"7 = -3.9203446 for A.sub.DD = 2 D: A'0 = 23.56555 A"0 = 14.368889 A'1 = -182.77804 A"1 = -87.219223 A'2 = 605.05684 A"2 = 244.35987 A'3 = -1 024.1053 A"3 = -337.92626 A'4 = 962.99613 A"4 = 241.37509 A'5 = -511.24120 A"5 = -85.757212 A'6 = 143.7355 A"6 = 12.008102 A'7 = -16.663562 for A.sub.DD = 2.5 D: A'0 = -28.307575 A"0 = 2.874459 A'1 = 190.37743 A"1 = 11.541159 A'2 = -445.545294 A"2 = -35.715782 A'3 = 512.44763 A"3 = 37.849808 A'4 = -315.3125 A"4 = -19.0199096 A'5 = 99.678413 A"5 = 4.2867818 A'6 = -12.731333 A"6 = -0.28934118 for A.sub.DD = 3 D: A'0 = 22.19555 A"0 = 57.071102 A'1 = -157.74065 A"1 = -357.09277 A'2 = 529.74104 A"2 = 1 000.8899 A'3 = -918.56382 A"3 = -1 509.5112 A'4 = 881.73279 A"4 = 1 311.576 A'5 = -475.73774 A"5 = -657.94254 A'6 = 135.48897 A"6 = 177.01095 A'7 = -15.888513 A"7 = -19.763759 ______________________________________ and, for possible intermediate additions whose value δ is between two above-mentioned addition values δ 1 and δ 1 +0.5, the envelope curves of these intermediate additions are deduced from the envelope curves corresponding to δ 1 and δ 1 +0.5 by the equations: ##EQU3##