Myopia control means
View Patent ↗Sets, kits or stocks of anti-myopia contact or spectacle lenses, along with methods for their use, that do not require a clinician to measure peripheral refractive error in the eyes of myopic patients. Extensive surveys have shown that lenses having peripheral powers or defocus set in accordance with central corrective power will cover almost all normal myopes not worse than −6 D central refractive error. In one example, a kit or set of lenses ( 50 , FIG. 15 ) can have multiple parts or sub-sets ( 52, 54 ) each comprising a compartmented container ( 56 a, 56 b ) with lenses ( 58 a, 58 b ) arranged according to increments of central corrective power ( 59 a, 59 b ). The lenses ( 58 a ) of the first part ( 52 ) have four steps ( 60 a, 61 a, 62 a, 64 a ) of peripheral power or defocus to pro vide therapeutic effect and, while the lenses ( 58 b ) of the second part ( 54 ) also have four steps ( 60 b, 61 b, 62 b, 64 b ), the level of therapeutic effect is higher. Other examples of sets, kits and stocks, as well as examples of lenses themselves, are disclosed together with methods of use.
1. A set, kit or stock of pre-manufactured lenses for use in the provision of an anti-myopia lens for an eye of a myopic patient, wherein:
each lens of the set, kit or stock has a central optical axis and a central optical zone surrounding and including said axis,
said central optical zone has a negative corrective refractive power between plano and −6.0 D, for correcting a positive central refractive error of a myopic eye,
said negative corrective refractive power varying in increments of a central refractive power within said set of lenses,
each lens has a peripheral optical zone surrounding said central zone,
said peripheral zone includes an incident angle with respect to the optical axis of about 30 degrees,
said peripheral zone of each lens has a positive peripheral refractive power relative to the refractive power of the central zone of that lens to thereby provide myopic peripheral defocus, said peripheral refractive power increases with increase of central refractive power within the set of lenses,
said peripheral defocus of any lens within the set, kit or stock of lenses is not greater than about 3.5 D, and
the lenses of the set, kit or stock are arranged in an orderly manner according to central refractive power, peripheral refractive power and/or peripheral defocus;
whereby a clinician is enabled, by selecting a lens for corrective power to provide or procure a lens to inhibit progression of myopia in the patient's eye without needing to first measure peripheral refractive error in the eye and to order a lens with customized peripheral power.
2. A set, kit or stock of pre-manufactured lenses according to claim 1 , wherein:
the increment of central refractive power is about −0.25 D,
the central refractive powers of the lenses fall within the range of about −0.25 D to about −6.0 D, and
the peripheral defocus of the lenses varies substantially proportionally with variation of the central refractive powers of the lenses within the range of +0.5 D to +3.0 D.
3. A set, kit or stock of pre-manufactured lenses according to claim 2 , wherein:
the peripheral defocus of the lenses of the set, kit or stock of lenses increases in steps with increasing central power such that multiple lenses with adjacent increments of central power have the same peripheral defocus,
whereby understanding or use of the set, kit or stock of lenses is facilitated by the clinician, manufacturer and/or the patient.
4. A set, kit or stock of pre-manufactured lenses according to claim 1 , wherein:
there are multiple subsets of lenses such that each subset comprises a plurality of lenses having the same central refractive power but different levels of peripheral defocus;
whereby, a clinician who knows the positive central refractive error of the myopic eye is enabled to conveniently (i) select the subset of lenses having the central refractive power judged to best correct said measured central error, (ii) select the lens from within the selected subset judged to have the level of peripheral power most appropriate to the patient's propensity for progressive myopia having regard to patient history, and (iii) try the selected lens on the eye to assess the patient's tolerance to peripheral blur caused by the selected lens.
5. A set, kit or stock of pre-manufactured lenses according to claim 4 , wherein: there are three levels of peripheral power in each said subset of lenses comprising low, medium and high levels of peripheral defocus;
whereby the clinician who has found that a selected lens having medium or high level of peripheral defocus is not acceptable to a patient is enabled to then select a lens with the same central power but a lower level of peripheral defocus.
6. A set, kit or stock of pre-manufactured lenses according to claim 1 , wherein:
the lenses of the set, kit or stock are contact lenses for trial or dispensing,
there are about 24 increments of central refractive power,
said central refractive power of the lenses in the set, kit or stock ranges from −0.25 D to about −6.0 D,
each increment of central power is about −0.25 D,
each lens of the set, kit or stock of lenses has a unique peripheral defocus, and
the amount of peripheral defocus of the lenses in the set, kit or stock of lenses increases substantially proportionally with increasing central refractive power of the lenses in the set, kit or stock of lenses.
7. A set, kit or stock of pre-manufactured lenses according to claim 1 , wherein:
the lenses of the set, kit or stock are contact lenses for trial or dispensing,
there are about 24 increments of central refractive power,
said central refractive power of the lenses in the set, kit or stock ranges from −0.25 D to about −6.0 D,
each increment of central power is about −0.25 D,
there are at least three steps of peripheral refractive power or defocus, and
each of said steps is about +0.5 D.
8. A set, kit or stock of pre-manufactured lenses according to claim 1 , wherein the patient uses a habitual lens that has a negative refractive power for correcting central refractive error in the myopic eye:
the lenses of set, kit or stock are trial spectacle lenses for use together with the patient's habitual lens,
each lens of the set, kit or stock has plano central refractive power and a different peripheral power from other lenses of the set, kit or stock,
each lens of the set, kit or stock is adapted for location in juxtaposed axial alignment with the habitual lens when fitted to the eye, and
the lenses of the set, kit or stock are arranged in an orderly manner according to peripheral power,
whereby a clinician is enabled to conveniently (i) select a lens from the set, kit or stock judged to have the level of peripheral power most appropriate to the patient's propensity for progressive myopia having regard to patient history, and (ii) try the selected lens in conjunction with the habitual lens on the eye to assess the patient's tolerance to peripheral blur.
9. A set, kit or stock of pre-manufactured lenses according to claim 8 , wherein:
the peripheral defocus of the lenses ranges between about +0.5 D and about +2.0 D, and
the peripheral power of the lenses of the set, kit or stock of lenses varies in increments not greater than about +0.5 D.
10. A set, kit or stock of pre-manufactured lenses according to claim 1 wherein the lenses are substantially rotationally symmetric in that the peripheral defocus is substantially the same for each peripheral quadrant of the lens.
11. A set, kit or stock of pre-manufactured lenses according to claim 1 wherein:
the peripheral defocus of the lenses of the set, kit or stock of lenses applies to the nasal quadrant or to the temporal quadrant of the lens so that, when a lens of the set, kit or stock of lenses is in use by a patient, the measured peripheral defocus of the lens affects the temporal or the nasal quadrant of the patient's retina, respectively.