Multifocal ophthalmic lens
AssigneeJohnson & Johnson Vision Products, Inc.
InventorJeffrey H. Roffman
Life of this patent
Estimating the term…
Abstract
An ophthalmic lens provides a cumulative ratio of distance to near focal length that is predominantly distance correction under high illumination, nearly evenly divided between distance and near correction under moderate illumination, and favoring again distance vision correction under low level illumination. The lens is specifically adjusted to match the patient's pupil size as a function of illumination level, in the preferred embodiment by applying pupil size parameters as a function of age. This lens has the properties of matching both the distribution of near and distance focal vision correction to the type of human activity typically undertaken in various illumination conditions, as well as matching particular lens dimensions to suit the size of the pupil as a function of illumination intensity.
Claims24
A multifocal ophthalmic lens, said lens comprising a body including a central region and at least first and second concentric annular regions, the first annular region extending around the central region, and the second annular region extending around the first annular region, and wherein:
- the central region has an optical surface area and a first optical power;
- the first annular region includes a plurality of concentric, annular first sub-regions, the first sub-regions being radially positioned in series and including a radially innermost first sub-region and at least one additional first sub-region;
- the radially innermost first sub-region has a second optical power, said second optical power differs from said first optical power, said first sub-region has an optical surface area about equal to or larger than the optical surface area of the central region;
- the sum of the optical surface areas of the central region and the first annular region that have the first optical power is proportional to the sum of the optical surface areas of the first annular region that have the second optical power to provide a lens which varies the optical power of the lens as a function of pupil diameter and luminance levels;
- and
- the remaining optical surface area of the lens having an optical power that when combined with the optical power of the central region and the first annular region, provides said lens with a dominant first optical power at high and low levels of luminance, and an approximately equal distribution between the first and the second optical powers at mid levels of luminance.
A multifocal ophthalmic lens for the treatment of presbyopia containing both a near optical power and a distance optical power, said lens containing an optical surface with a central region having said distance optical power, a first annular region exterior to said central region and containing an about equal or more near optical power area than the total distant optical power area in the central and first annular regions combined, said optical area of the central region and the optical area of the annular region arranged to vary the optical power in response to pupil diameter and luminance and a second annular region exterior said first annular region and containing sufficient distance optical power area such that the total distance optical power area in the central, first annular and second annular regions combined is greater than the total near optical power area in the central, first annular and second annular regions combined, said lens providing a dominant distance optical power correction at high and low levels of luminance, and an approximately equal distribution between near and distance optical power correction at mid levels of luminance.
A multifocal contact lens for use in the treatment of presbyopia, said lens comprising a body including a central region and at least first and second concentric annular regions, the first annular region extending around the central region, and the second annular region extending around the first annular region, and wherein:
- the central region has an optical surface area and a first optical power;
- the first annular region includes a plurality of concentric, annular first sub-regions, the first sub-regions being radially positioned in series and including a radially innermost first sub-region and at least one additional first sub-region;
- the sum of the optical surface areas of the central region and the first annular region that have the first optical power being proportional to the sum of the optical surface areas of the first annular region that have a second optical power, said second optical power differs from said first optical power, to provide a lens which varies the optical power of the lens as a function of the wearer's pupil diameter in response to variations in luminance levels encountered by the wearer;
- and
- the remaining optical surface area of the lens having an optical power that provides said wearer with a contact lens which varies the combined optical power of the central region, first annular region and the second annular region as a function of luminance, with a dominant first optical power at pupil diameters of less than 25% of maximum pupil diameter and greater than 75% of maximum pupil diameter, and an approximately equal distribution between the first and the second optical powers at pupil diameters greater than 40% and less than 60% of maximum pupil diameter.
Dependencies are inferred from the claim text.