Disclosure of Invention
The present invention aims to provide a continuous-zoom contact lens capable of correcting ametropia of an eyeball and correcting an imaging focal position in a peripheral region of a retina.
The continuous variable focus contact lens of the present invention comprises: a central optical zone, and a peripheral zone.
The central optical zone comprises a first optical zone and a second optical zone, wherein the first optical zone is a circular area which is surrounded by a central optical axis of the continuous zooming contact lens as a circle center and has a radius of 1.5 +/-1.0 mm. The second optical zone extends radially outward from the periphery of the first optical zone to the peripheral zone.
The refractive power of the continuous zooming contact lens is continuously changed along the radial direction, and the average change rate of the refractive power is less than 0.25D/mm in the first optical zone and more than 0.25D/mm in the second optical zone.
Preferably, the diopter power of the continuous-zoom contact lens is continuously changed radially outward from the central optical axis as a starting point.
Preferably, the refractive power of the second optical zone increases by a positive value radially outward, and the difference between the refractive power at the periphery of the second optical zone and the refractive power at the central optical axis is not more than 1.5D.
Preferably, the refractive power of the second optical zone increases by positive values radially outward, and the average change rate of the refractive power of the second optical zone is greater than 0.75D/mm.
Preferably, the first optical zone has an initial refractive power that is negative, and the refractive powers of the first and second optical zones increase radially outward by positive values.
Preferably, the first optical zone has a base curve radius of 8.0 to 9.0mm and an aspheric conic constant (K) greater than 0.
Preferably, the outer edge of the second optical zone is located at a radius of 0.5 to 4.0mm from the central optical axis of the continuous variable focus contact lens.
Preferably, the peripheral zone extends outward from the outer edge of the second optical zone, and the curvature change of the peripheral zone is adjusted according to actual requirements, so as to achieve proper lens thickness change and reduce the generation of aberration.
Preferably, the refractive power of the first optical zone is gradually increased from the central optical axis as a starting point, and the refractive power of the second optical zone is gradually increased when the refractive power of the first optical zone is continued.
Preferably, the increasing rate of the refractive power of the first optical zone is lower than that of the second optical zone.
The invention has the beneficial effects that: the continuous zooming contact lens can correct the ametropia of an eyeball by continuously changing the dioptric power of the first optical area and the second optical area along the radial direction, solves the problem that the conventional multifocal contact lens has imaging jump or light splitting phenomenon so that a wearer has dizzy or bad adaptation and other adverse reactions, and simultaneously corrects the focus position of imaging in the peripheral range of the retina so as to achieve effective pressure relief for the eye.
Detailed Description
The invention relates to a continuous zooming contact lens, which can correct the ametropia of an eyeball by continuously changing the dioptric power of the continuous zooming contact lens along the radial direction, solves the problem that the conventional multifocal lens has imaging jump or light splitting phenomenon so that a wearer has dizzy or bad adaptation and other adverse reactions, and simultaneously corrects the imaging focal position in the peripheral range of retina so as to achieve effective pressure relief for eyes.
The center of vision of the eye is more sensitive and accurate than peripheral vision, and near the center of the retina there is a small depression, called the fovea maculata (also called the macula), of about 0.2mm diameter, which is the most acute location of vision and is also at the center of vision of the human eye. The peripheral region around the macula is significantly less visually sensitive, and when 5 degrees off the visual axis, the resolution drops to one third of the central value of the macula. However, since the cornea is spherical except for the central area, and the peripheral area is not spherical, if the refractive indexes of the contact lenses are consistent, when the eye looks far, the light rays are refracted like parallel light through the crystalline lens and then projected into the central fovea of the macula lutea, and the ciliary muscle relaxes to see far for a long time, and the eye will not be fatigued, on the contrary, if the eye looks for a long time at a near object, the ciliary muscle is forced to focus on the peripheral area of the retina, although the near object is clear, and the imaging focus does not fall on the retina, so as to form hyperopic defocus, and at this time, in order to obtain better imaging, the ciliary muscle is forced to adjust the curvature of the crystalline lens, and the burden is increased. Therefore, the present invention continuously changes the dioptric power of the contact lens along the radial direction, so that the continuous zooming contact lens can correct the ametropia of the eyeball, solve the problem that the imaging jump or the light splitting phenomenon of the existing multifocal contact lens causes the wearer to have the bad adverse reactions such as dizzy or poor adaptation, and simultaneously correct the focus of the imaging in the peripheral range of the retina.
Referring to fig. 5 and 6, the continuous-zoom contact lens 1 of the present invention includes a central optical axis L, a central optical zone 11, and a peripheral zone 12 extending radially outward from the central optical zone 11. The central optical zone 11 is a visual zone for providing vision correction, and has a dioptric power for providing vision correction, and the peripheral zone 12 is designed to increase the suitable wearing area of the continuous variable focus contact lens 1, so that the continuous variable focus contact lens 1 can be stably attached to the cornea 94 of the eye 9 of a wearer, and the peripheral zone 12 is a non-primary visual zone, so that the peripheral zone 12 may not have a clear visual effect.
The central optical zone 11 includes a first optical zone 111 and a second optical zone 112. The first optical zone 111 is a circular area surrounded by the central optical axis L of the continuous variable focus contact lens 1 and having a radius of 1.5 ± 1.0 mm. The radius of curvature of the Base Curve (BC) of the first optical zone 111 is between 8.0 and 9.0mm, the conic constant (K) is greater than 0, and the refractive power varies continuously along the radial direction, and with the central optical axis L as the axisymmetric center, the average variation rate of the radial refractive power is less than 0.25D/mm, preferably less than 0.125D/mm. When the eye 9 of the wearer is wearing the continuous zoom contact lens 1 and gazing far, the distant scene is imaged onto the macular fovea 911 of the retina 91 by refractive correction of the first optical zone 111. The initial diopter power of the first optical zone 111 is adjusted according to the needs of the wearer, and if the wearer is a myopic patient, the diopter power suitable for the patient is used as the initial value.
The second optical zone 112 extends outward from the first optical zone 111, and the distance between the outer edge and the central optical axis L of the continuous variable focus contact lens 1 is less than a radius of 4mm, preferably 2.5 to 3.5mm, however, the distance between the second optical zone 112 and the central optical axis L is greater than 4mm, and still does not affect the whole visual range, i.e. the visual range of the whole central optical zone 11 is not affected, so that the distance between the second optical zone 112 and the central optical axis L is less than a radius of 4mm but does not absolutely exceed a radius of 4mm in the visual range of human eyes, and obviously only the labor cost is increased if the design of the continuous variable focus contact lens 1 has a dioptric power in the portion outside the visual range. The refractive power of the second optical zone 112 continuously changes along the radial direction, and taking the central optical axis L as the axisymmetric center, the average rate of change of the radial refractive power is more than 0.25D/mm, and preferably, the average rate of change of the radial refractive power is more than 0.5D/mm. The continuous-zoom contact lens 1 increases the refractive power of the second optical zone 112, i.e. the refractive power of the second optical zone 112 is greater than the refractive power of the first optical zone 111, and the average change rate of the refractive power of the second optical zone 112 is greater than the average change rate of the refractive power of the first optical zone 111, so that the imaging focus of the object corrected by refraction through the second optical zone 112 falls in front of the peripheral range 912 of the retina 91 to generate myopic defocus, thereby the ciliary muscle 92 does not need to exert excessive force when viewing near objects, the curvature of the crystalline 93 is reduced to adjust focusing, and the eye can achieve effective pressure relief. It should be noted that the numerical ranges below 0.25D/mm and above 0.25D/mm are defined, that is, less than or equal to (not greater than) 0.25D/mm and greater than or equal to (not less than) 0.25D/mm, respectively.
In practical design, although the average variation rate of the refractive power of the first optical zone 111 is not greater than 0.25D/mm, the first optical zone 111 is not limited to be in an increasing condition, and the first optical zone can also be in a decreasing condition after increasing, only the average variation rate of the refractive power needs to be controlled to be not greater than 0.25D/mm, and similarly, the second optical zone 112 can also be. However, in view of the difficulty of manufacturing technology and the avoidance of image skipping, it is preferable that the refractive power of the first optical zone 111 is gradually increased from the central optical axis L, the refractive power of the second optical zone 112 is gradually increased over the refractive power of the first optical zone 111, and more preferably, the increasing rate of the refractive power of the first optical zone 111 is lower than the increasing rate of the refractive power of the second optical zone 112.
The peripheral zone 12 extends outwardly from the outer edge of the second optical zone 112, and the outer edge of the peripheral zone 12 is spaced from the central optical axis L of the zoom lens 1 by a distance of not more than a radius 8.0 mm.
By establishing the initial power of the first optical zone 111 and the power change of both the first optical zone 111 and the second optical zone 112 of the contact lens 1, the contact lens 1 can be manufactured according to conventional manufacturing methods. The conventional production method may, for example, be: and press forming, rotary die forming, and turning …. The method for manufacturing the continuous variable focus contact lens 1 of the present invention is not limited, and the material is not limited, and examples of the material include, but not limited to, a copolymer of Hydroxyethyl methacrylate (HEMA) and Methacrylic acid (MAA), hydrophilic hydrogel (hydrogel), relatively hydrophobic hydrogel (Silicon hydrogel), and hard highly oxygen-permeable silicone fluoropolymer.
When the wearer's eye 9 wears the continuous zoom contact lens 1 and looks at a near object, the object near the central optical axis L is formed on the fovea 911 of the retina 91 through the first optical zone 111, and the object far away from the central optical axis L is formed on the peripheral area 912 of the retina 91 through the second optical zone 112 of the continuous zoom contact lens 1, because the second optical zone 112 has a higher dioptric power design than the first optical zone 111, so that the object is formed in front of the peripheral area 912 of the retina 91 through the second optical zone 112, forming myopic defocus, thereby the ciliary muscle 92 does not need to exert excessive force, the curvature of the crystal 93 is reduced, the focusing is adjusted, and the eye 9 can achieve effective pressure relief.
When the continuous variable focus contact lens 1 satisfies the condition that the refractive power of the second optical zone 112 increases by a positive value radially outward, and the difference between the refractive power at the periphery of the second optical zone 12 and the refractive power at the central optical axis L is not greater than 1.5D, the image on the retina 91 is sufficiently clear when viewing near objects, and the occurrence of tight contraction of the ciliary muscle 92 can be effectively reduced, so as to reduce fatigue caused by long-time near-distance fixation, and to relieve the burden of the eye 9.
By adjusting the variation of the dioptric power of the second optical zone 112, the increase of the myopia of the child can be effectively reduced. The reason for this is that most of children's eyes are presbyopia, and the axis of the eye will increase continuously during the development process, gradually moving towards the general vision. In the process of the increase of the eye axis, if the existing single-focus lens is used for myopia correction and the scene is watched in a short distance for a long time, the eye axis of the eyes of the children is easily lengthened excessively, so that the myopia is caused. Therefore, adjusting the variation of the dioptric power of the second optical zone 112 of the continuous-zoom contact lens 1 can effectively improve the above-mentioned problem, i.e. increasing the dioptric power of the second optical zone 112 by a positive value outwards in the radial direction, and making the average variation rate of the dioptric power of the second optical zone 112 greater than 0.75D/mm, so that the increase of the myopic power can be effectively reduced when a child wears the continuous-zoom contact lens for correcting the vision.
By adjusting the initial diopter power of the first optical zone 111 of the continuous variable focus contact lens 1 and adjusting the diopter power variation of the whole continuous variable focus contact lens 1, the continuous variable focus contact lens is suitable for the presbyopic patient to wear. The adjustment is to make the first optical zone 111 have zero or negative dioptric power to adapt to the emmetropia or myopia degree of the wearer for viewing the distant scene, and to increase the dioptric power of the second optical zone 112 by a positive value outward in the radial direction to increase to the distance vision degree of the wearer for viewing the medium and near scenes.
Preferred embodiments of the present invention will be illustrated below, however, before the present invention is described in detail by the preferred embodiments, it should be noted that in the following description, similar elements are denoted by the same reference numerals.
[ example 1]
Referring to fig. 5, 6 and 7, the continuous variable focus contact lens 1 according to embodiment 1 of the present invention is suitable for a pressure relief lens design for relieving the burden of close-distance gaze on the eye 9, wherein the continuous variable focus contact lens 1 is formed by UV light irradiation polymerization compression molding using HEMA aqueous gel, and comprises a first optical zone 111, a second optical zone 112, and a peripheral zone 12, which are defined by using the central optical axis L of the continuous variable focus contact lens 1 as a center and being surrounded by radii of 1.5mm, 3mm and 7.1mm, respectively. The second optical zone 112 extends outwardly from the outer edge of the first optical zone 111, and the peripheral zone 12 extends outwardly from the outer edge of the second optical zone 112. The thickness of the continuous-zoom contact lens 1 at the central optical axis L is 0.08mm, the radius of base curvature of the first optical zone 111 is 8.6mm and the conic constant (K) is 0.3, the initial diopter power of the first optical zone 111 is-3.0D, the radially outward average rate of change of diopter power of the first optical zone 111 is +0.125D/mm, the radially outward average rate of change of diopter power of the second optical zone 112 is +0.875D/mm, and the diopter power of the edge of the second optical zone 112 to radius 3mm is-1.5D.
The continuous zooming contact lens 1 can avoid the generation of blurred images or poor adaptation caused by image skipping or light splitting phenomenon due to discontinuous step sharp change of the conventional multifocal contact lens by the aspheric surface and continuous zooming design of the first optical zone 111 and the second optical zone 112.
Moreover, the variation of the dioptric power of the first optical zone 111 does not affect the imaging quality of the central fovea 911, but increases the dioptric power by positive value from the range of the second optical zone 112 to the radius of 3mm, and reaches-1.50D, so that the imaging focus of the peripheral range 912 of the retina 91 is forward, thereby generating myopic defocus, thereby relieving the tightness of the ciliary muscle 92 caused by adjusting the curvature of the crystalline 93 and effectively reducing the load of the eye 9. It should be noted that if the difference between the dioptric power of the continuous zoom contact lens 1 at the position 3mm from the central optical axis L and the dioptric power of the central optical axis L is greater than 1.5D, the excessive myopic defocus will adversely affect the imaging quality, and therefore, when the difference between the dioptric power at the position 3mm from the central optical axis L and the dioptric power at the position L is not greater than 1.5D, the continuous zoom contact lens will have the effects of imaging quality and relaxing the ciliary muscle 92 at the same time, and the long-term near-eye fatigue problem of most of the existing contact lenses with spherical design in the light wearing area is effectively solved.
[ example 2]
Referring to fig. 5, 6 and 8, embodiment 2 of the present invention is suitable for reducing myopia in children, and is substantially the same as embodiment 1, except that: the continuous zoom contact lens 1 is formed by UV light irradiation polymerization mold pressure molding of Silicon hydrogel (Silicon hydrogel), the first optical zone 111, the second optical zone 112 and the peripheral zone 12 are defined around the central optical axis L and are respectively defined by radii of 1.0mm, 3.0mm and 7.0mm, the radius of base curvature of the first optical zone 111 is 8.5mm and the conic constant (K) is 0.8, the initial refractive power of the first optical zone 111 is-3.0D, the average change rate of the refractive power of the first optical zone 111 radially outward is +0.125D/mm, the average change rate of the refractive power of the second optical zone 112 radially outward is +1.50D/mm, and the refractive power of the peripheral optical zone 112 to the edge of 3mm radius is + 0.125D.
The continuous zoom contact lens 1 can avoid the phenomenon of image skipping or light splitting caused by discontinuous step sharp changes of the conventional multifocal contact lens and further the generation of the blurred image phenomenon caused by the image skipping or light splitting through the aspheric and continuous zoom designs of the first optical zone 111 and the second optical zone 112, and the second optical zone 112 can generate the imaging design of myopic defocus in the peripheral range 912 of the retina 91 through the average change rate of the dioptric power thereof along the radial direction to the outside greater than +0.75D/mm, so as to improve the design of hyperopic defocus in the peripheral range of the retina caused by the common frame glasses and the spherical contact lenses, thereby the derived physiological stimulation of the increase of the ocular axis can be avoided, and the excessive elongation of the ocular axis of the eyes of the children can be avoided, therefore, the embodiment 2 can control the growth of the myopic children and correct the ametropia.
[ example 3]
Referring to fig. 5, 6 and 9, embodiment 3 of the invention is a continuous-focus contact lens 1 suitable for use with presbyopic patients, which is substantially the same as embodiment 1 except that: the continuous variable focus contact lens 1 is formed by polymerizing a mold pressure through UV light irradiation with a water gel (Hygrogel), the first optical zone 111, the second optical zone 112, and the peripheral zone 12 are defined around the central optical axis L as a center and with radii of 1.0mm, 3.0mm, and 7.0mm, respectively, the initial diopter of the first optical zone 111 is zero, the average rate of change of diopter of the first optical zone 111 radially outward is +0.25D/mm, the average rate of change of diopter of the second optical zone 112 radially outward is +1.0D/mm, and the diopter of the edge of the second optical zone 112 to the radius of 3mm is + 2.5D.
The continuous zooming contact lens 1 can avoid the phenomenon of blurred images caused by the phenomenon of image skipping or light splitting due to discontinuous step sharp changes of the conventional multifocal contact lens by virtue of the aspheric surface and continuous zooming design of the first optical zone 111 and the second optical zone 112, the first optical zone 111 can be used for a wearer to watch long-distance scenes, and the second optical zone 112 can be used for watching short-distance scenes and can be used as presbyopic glasses.
From the above description, the advantages of the present invention can be summarized as follows:
firstly, the continuous-zoom contact lens 1 of the present invention can correct the ametropia of the eyeball and correct the imaging focal position of the peripheral area 912 of the retina 91 and maintain clear optical quality without aberration, jump image or light splitting phenomenon by continuously changing the refractive powers of the first optical zone 111 and the second optical zone 112 along the radial direction.
Secondly, by adjusting the variation of the dioptric power of the continuous zooming contact lens 1, the difference between the dioptric power at the position where the distance of the central optical axis L is equal to the radius of 3mm and the dioptric power at the position of the central optical axis L is smaller than 1.5D, so that the accommodation power of ciliary muscles 92 on crystalline lens 93 can be effectively reduced, the fatigue caused by long-time short-distance use of eyes can be reduced, and the burden of the eyes 9 can be relieved.
Thirdly, the increase of the myopia degree of the child can be effectively reduced by increasing the refractive power of the second optical zone 112 by a positive value in the radial direction outwards and making the average change rate of the refractive power of the second optical zone greater than 0.75D/mm.
Fourthly, by adjusting the initial diopter power of the first optical zone 111 and then adjusting the diopter power change of the whole second optical zone 112, the diopter power is gradually increased to the hyperopia power corresponding to the wearer, so that the presbyopic glasses are suitable for the presbyopic patient to see far and near.
In summary, the continuous variable focus contact lens 1 of the present invention continuously changes its dioptric power along the radial direction, so that the continuous variable focus contact lens 1 can correct the ametropia of the eyeball, and solve the problem of the conventional multifocal lens having the adverse reactions such as dizzy and the like caused by the image skipping or light splitting phenomenon of the multifocal lens, and at the same time, the focal position of the image in the peripheral range 912 of the retina 91 is corrected to achieve the effective pressure relief for the eye, so the purpose of the present invention can be achieved.
The above description is only an example of the present invention, and the scope of the present invention should not be limited thereby, and the invention is still within the scope of the present invention by simple equivalent changes and modifications made according to the claims and the contents of the specification.