Multifocal lens
AssigneeRotlex (1994) Ltd.
InventorEliezer Keren
Life of this patent
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Abstract
A multifocal lens having far and near vision zones is presented. The lens comprises a substrate in the form of a progressive addition lens and a modulation formed on a surface of the substrate. The substrate lens has far and near vision zones, selected in accordance with respective prescribed values of optical power required for the patient's eye at his distance and reading vision, and an intermediate transition region between the far and near vision zones. The modulation is of kind producing locally variable power addition such that the far and near vision zones of the multifocal lens are wider than the far and near vision zones of the substrate.
Claims11
A multifocal lens having far and near vision zones, the multifocal lens comprising a combination of a progressive addition lens and a diffractive element wherein:
- (a) said progressive addition lens is a substrate carrying said diffractive element, which is in the form of a modulation on the surface of the substrate:
- said substrate has refractive power distribution defining far and near vision zones, selected in accordance with respective prescribed values of optical power required for a patient's eye at the patient's distance reading vision, and an intermediate transition region between the far and near vision zones;
- and
- (b) said modulation produces locally variable optical power addition to the optical power of the substrate, said locally variable optical power addition being maximal within said intermediate transition region and decreasing gradually towards the far and near vision zones of the substrate, said far and near vision zones of the multifocal lens being thereby wider than said far and near vision zones of the substrate.
Dependencies are inferred from the claim text.