The application enjoys in the senior interest of the U.S. Provisional Patent Application NO.60/193493 that files an application on March 31 of 2000 according to 35U.S.C. § 119 (e) request.
Astigmatism is the defective of the eyes that will proofread and correct with the eyeglass with non-spherical structure.Joining the above-mentioned structure that mirror Dan Shangchang represents with right cylinder and can make at least a portion of lens surface have the shape of double-curved surface part the patient.Double-curved surface is to be rotated and the surface or the entity that form around the axis of non-axis own by a circle.For example, annular solid has toric shape, and the double-curved surface of eyeglass partly is the little oval part with major axis and minor axis on the double-curved surface.Owing to adopt this nonaxisymmetric structure, must keep the correct rotational positioning of eyeglass.Must be noted that other eyeglass for example can provide bi-focal to proofread and correct or the eyeglass of many focus correction, also is nonaxisymmetric, therefore has specific orientation, outside this orientation, poor-performing.
Astigmatism usually with other refraction error for example myopia or long sight interrelate, so the double-curved surface contact lens usually also can provide some bear or positive spherical corrections.Though the concave surface of the contact lens shape of back in other words generally is a sphere, in the occasion with the lenses which correct astigmatism, the back of contact lens has the double-curved surface shape usually, that is to say, the sweep of face has major axis and minor axis after the eyeglass.The eyeglass back along the radius-of-curvature of long axis direction greater than radius-of-curvature along short-axis direction.Toric major diameter is usually less than the diameter of whole eyeglass; And be cut into an initial spherical base curve.In addition, the front of lens region and/or back can have a spherical part that helps apart from refraction correction, and the outside by eyeglass provides spherical correction in the front in other words usually.Certainly, some structure has the double-curved surface that is positioned on the front, proofreaies and correct and all can provide spherical in front or in the back.
Though lens can be by mirror holder positioning and fixing rigidly,, the double-curved surface contact lens must stable position and cylinder correction roughly is stabilized on the correction position of eyes.In the prior art, well-known soft contact lens has been used for correction of astigmatism.Generally speaking, these contact lens rely on the stabilizing mechanism of several types or antihunt means and make eyeglass location correctly in eyes.Usually in the eyeglass front or in the back or between forward and backward, add member and form the stable region of contact lens.This align member will utilize the acting force of nictation to the eyelid of generation.When eyelid touching contact lens, they can push eyeglass downwards, make it come on the cornea and elevation angle surface characteristics is moved.
Can adopt a kind of so-called " sphenoid " " prism " stable region in other words, wherein, the bottom of eyeglass is thicker than top, therefore, move greatly than palpebra inferior in the upper eyelid, and the upper eyelid will apply big acting force to contact lens and just can be easier to the bottom of contact lens is moved down, thereby automatically makes contact lens rotate and enter required orientation along cornea.In addition, contact lens also can adopt the antihunt means of a kind of so-called " peripheral stable region " (writing a Chinese character in simplified form of " stable region on every side "), and these antihunt means comprise a stable region that surrounds but do not comprise central lens region.
United States Patent (USP) NO.4573774,5125728 and 5020898 and the open example of above-mentioned excessively prism ballast of PCT publication NO.WO98/45749.Other contact lens location structure comprises makes district and inferior segment make the method thinner than thick central area, this structure is shown in United States Patent (USP) NO.4095878 and 5650837. in addition, also raceway groove or spine can be set on contact lens, for example see PCT publication NO.AU92/00290.
United States Patent (USP) NO.5020898 discloses a kind of double-curved surface contact lens with the stable region that is distributed in outside the lens region of front, and the thickness in aforementioned stable district is thickeied gradually from top to two point of maximum thickness near lower periphery of contact lens.
United States Patent (USP) 5125728 also discloses a kind of ballast portion that thickens maximum ga(u)ge from the top of contact lens to its following peripheral, both sides, the maximum ga(u)ge of this ballast portion is arranged on as close as possible lens edge, is complementary on these ballast portion and on every side cornea and the conjunctiva and limits eyeglass and rotate thereby make.Above and below central lens region part the strip of the minimum no stable region of a kind of resistance is set in the vertical intermediate of contact lens.Above-mentioned patent declares, the strip of above-mentioned no stable region and thicker stable region and can form a kind of improved stabilization mechanism near combining than thickness portion of lens periphery.
At last, PCT publication NO.WO98/45749 has set forth a kind of stabilization eyeglass that has by the prism of lens region.The diameter of the front and back lens region of its eyeglass is chosen to press close on the controlled front thickness of the top and the lower part of lens region when being combined into eyeglass.
Except eyeglass the relative capacity of constant position on the cornea, other factor also can influence the performance of various rock-steady structures.For example, certain structures is better than other structures at a following aspect or several aspect aspect several: the gross thickness that reduces the double-curved surface contact lens is to bring physiological benefit to the wearer; Easy to manufacture; Reduce the lens parameters project; Clinical performance comprises the consistance that cooperates between wearer's comfort level and the refracting power.About wearer's comfort aspect, in general, eyeglass is thin more, the surface is level and smooth more, and it is comfortable more that the wearer will feel.In addition, well-known, do lens periphery to such an extent that also can increase comfort level than approaching and making certain shape.
The subject matter of existing double-curved surface contact lens structure is that the variation in orientation is big.And/or for certain structure, the comfort level that various wearers feel differs greatly.Except the structure and material of eyeglass, patient's factor also has influence on double-curved surface contact lens location within the eye, and increases the variation in eyeglass orientation.The shape of characteristics that above-mentioned patient's factor is for example blinked and vision parameter such as eyelid, cornea and conjunctiva and structure can produce unfavorable interaction (for example asymmetric); Or with the interaction force deficiency of contact lens.But the many problems relevant with the mechanism of prior art can be summed up as the relevant problem of inefficacy of stabilization mechanism that the interreaction force maximum that will make eyelid reduces the variation in the eyeglass orientation between each wearer.
Although in this field, did a lot of effort, be necessary that still the double-curved surface contact lens is had and make stabilization feature consistent more between all kinds of wearers.
General introduction of the present invention
According to the present invention, provide a kind of contact lens with improved thickness and stable region structure.Contact lens of the present invention can reduce the difference of the lens orientation between the well-known wearer.And contact lens of the present invention the time can make between stabilizing mechanism and the eyelid in nictation and more effectively interact, and reasonably has one and make the wearer needed surrounding zone that feels comfortably cool.
Therefore, on the one hand, the invention provides a kind of contact lens, it has one and has the fundamental surface (comprising convex front surface and back concave surface) of the sphere of being roughly and the contact lens body of the neighboring between above-mentioned convex front surface and back concave surface, in abutting connection with surrounding zone of formation, neighboring of above-mentioned convex front surface.Thickness between above-mentioned mirror body tool convex front surface and the back concave surface, and be nonaxisymmetric, thereby form a upper periphery and a following peripheral, and, form a vertical meridian from upper periphery towards the following peripheral, and form a horizontal meridian perpendicular to above-mentioned vertical meridian.Have a plurality of zones in the above-mentioned convex front surface, comprise the inner region that surrounds by the surrounding zone and roughly be positioned at the lens region of the central authorities of inner region.In addition, contact lens has a prism ballast part, and like this, the thickness of eyeglass increases towards the following peripheral from upper periphery gradually along vertical meridian in the ballast portion of inner region at least.Above-mentioned inner region have one on the top between the upper limit of lens region and inner region, one at the lower part between the lower limit of lens region and inner region and the center section between top and lower part.Form above-mentioned ballast portion in one or more in above-mentioned top, center section and lower part, this ballast portion is except that surrounding zone and lens region, have a series of continuous horizontal sections, and stride across one section distance of at least 20% along the minimum dimension of top, center section and lower part that vertical meridian is measured, wherein, each horizontal section has roughly homogeneous thickness, and this variation in thickness is no more than 30 μ m or about 20% with big being as the criterion of absolute value.In one embodiment, the variation in thickness in the continuous horizontal section of each of contact lens is no more than 15 μ m or about 10%, with big being as the criterion of absolute value.
In one embodiment, ballast portion all only forms in top, center section and lower part.In another embodiment, ballast portion all only forms in two in top, center section and lower part.In yet another embodiment, ballast portion forms in whole 3 parts in top, center section and lower part.
In a preferred embodiment, the band gradient the surrounding zone in thickness change less than 250 μ m/mm about, more suitably be less than about 200 μ m/mm.
In an alternative embodiment, contact lens of the present invention has one and has and comprise the roughly spherical fundamental surface of convex front surface and back concave surface and the contact lens body of the neighboring between convex front surface and back concave surface.Form the surrounding zone of its thickness in abutting connection with place, lens periphery limit to lens periphery limit attenuate.Above-mentioned mirror body has the thickness between convex front surface and the back concave surface, and is nonaxisymmetric, thereby forms upper periphery and following peripheral.Form a vertical meridian from this upper periphery to the following peripheral, form a horizontal meridian in addition perpendicular to it.Have a plurality of zones in the convex front surface, comprise an inner region and a lens region that roughly is positioned at the central authorities of inner region of surrounding and have the prism ballast part by the surrounding zone, wherein, at least in the prism ballast of inner region part the thickness of eyeglass increase gradually to the following peripheral along the vertical meridian direction from upper periphery.Between above-mentioned inner region and the neighboring along 225 ° meridianal distance less than 1.4mm about.
According to one aspect of the present invention, a kind of contact lens of mold pressing has a full mold pressing (just the front and back all is mold pressing) contact lens body, and this contact lens body has general features recited above.As previously mentioned, the contact lens of mold pressing is distinguished within it has a prism ballast part, between above-mentioned inner region and the neighboring along 225 ° meridianal distance less than 1.8mm about.On the other hand, promptly also wish in addition, between above-mentioned inner region and the neighboring along 270 ° meridianal distance less than 2.1mm about, and along 180 ° meridianal distance less than 1.3mm about.
Desirablely be, surround and be roughly annular by the surrounding zone around the zone of lens region, that is to say, in inner region, form one section top distance A to the surrounding zone, and in inner region, form a pars infrasegmentalis apart from B to the surrounding zone along vertical meridian from lens region along vertical meridian from lens region.For the contact lens of the band prism ballast of mold pressing, above-mentioned annular region is in following scope: 0.33A≤B≤A, and to the contact lens of all band prism ballast, its annular region is then in following scope: 0.55≤B≤A.
The combination of one or more of each characteristic recited above and These characteristics is included within the scope of the present invention, as long as the not mutual contradiction of the characteristics that comprised in the described combination.
By understanding the present invention and additional features and advantage admirably referring to the explanation of doing below in conjunction with exemplary accompanying drawing, part identical in the accompanying drawing is represented with same numeral.
The explanation of preferred embodiment
The contact lens that the invention provides a kind of stabilization especially has the contact lens to the cylinder correction of astigmatism.More in a broad sense, the invention provides and have the contact lens that can interact with action nictation of eyelid and when rotating, make the stable surface, the elevation angle of eyeglass.The stability of rotating is useful for any nonaxisymmetric contact lens, and for example, toric lens or many focus lenses must keep its rotational orientation correctly to proofread and correct.But, must understand, also wish to have rotational stability for other special eyeglasses.
In the following description, a plurality of surfaces of contact lens of the present invention and thickness will illustrate that eyeglass is flattened in the drawings referring to see-through view before simple.Contact lens has basic sphere curved surface usually, and its front is a convex surface, and the back then is a concave surface.Its various surfaces and lens region are by foundation phantom system or processing.For the sake of simplicity, with shown in front view flatten, and remove basic spheroid, like this, just eliminated and the corresponding hacures of basic sphere curved surface, so can clearly show that concrete surface of the present invention and thickness.In a preferred embodiment, contact lens of the present invention has negative spherical optical power range correction and is used for the double-curved surface of cylinder correction.
Fig. 1 illustrate the bent type of the present invention contact lens 20 flattening and not with the expression hatched simple front view in each zone wherein.Above-mentioned contact lens 20 has the eyeglass body of being made by suitable soft material or rigid material.Soft contact lens is generally by making such as hydrophilic materials such as hydroxyethyl methacrylic ester, organic metal material, silicon rubber, silicone-hydrogel, urethanes.In addition, also can adopt and make such as the ventilative material of rigidity such as siloxane acrylate or fluorosilicone acrylate.Above-mentioned eyeglass body has a total sphere curved surface, this curved surface have one be used for contacting with cornea and with face outer relative spill back, convex front.
Referring to Fig. 1, contact lens 20 has a lens region 22, a surrounding zone 24 and an inner region 26 that is defined by above-mentioned surrounding zone, and wherein, lens region 22 constitutes the part of inner regions 26.In addition, above-mentioned inner region 26 also can form between lens region and surrounding zone.As hereinafter will illustrating, lens region 22 can be a shape circular, toroidal shape or that other are specific.The radial dimension of surrounding zone 24 (width) can be uniformly, also can change.In shown exemplary embodiments, the radial dimension of 24 upper ends 30, surrounding zone is less, and in the lower end 32 radial dimension broad.In other words, inner region 26 has circular periphery stable region periphery 34 in other words, this in week the vertical meridian that runs through of edge in other words center line Z-Z ' depart from contact lens 20 tops a little.Should be noted that between lens region 22, surrounding zone 24 and the inner region 26 among the figure clearly outline line and do not mean that discontinuously or have knuckle at these positions, in fact, is curve transition gradually between each district of exemplary contact lens of the present invention.
The edge 36 of eyeglass is the intersection of convex front surface and back concave surface.Surrounding zone 24 is preferably with gradient, so that make lens edge 36 thinner than circular stable region periphery 34, about this point, surrounding zone 24 preferably has the taper surface (though this taper surface is to be superimposed upon on the following sphere curved surface) of a part.In addition, surrounding zone 24 can have a kind of sphere curvature or for example any suitable curved surface of other curvatures (shape just) of part.
We be sure of that the various features of contact lens 20 of the present invention can make them wear more comfortable than other similar contact lens.In fact, some clinical testing is reached a conclusion: the patient is more more satisfied than similar contact lens for the reaction of the level of comfort of contact lens of the present invention.
Inner region 26 can be divided into 3 parts along vertical meridian Z-Z '.Specifically, be to be divided into 3 parts in upper, middle and lower, top 40 is between the top of the top of stable region periphery 34 and lens region 22.Draw by imaginary line 42 perpendicular to meridian Z-Z ', center section 44 is between second cross line 46 of meridianal cross line 42 and lens region 22 bottoms, at last, lower part 48 is between the bottom of second cross line 46 and stable region periphery 34, therefore, lens region 22 all is positioned within the center section 44.
Among the application, inner region 26 is divided into the isolated area that can form the specific surface of stability with top 40, center section 44 and lower part 48.But, should be understood that the cut-off rule the 42, the 46th between each zone in this respect, changeable, also can be non-linear.In one aspect, the present invention relates to the surface, concrete stable region or the prism ballast surface/thickness of one or more parts that can define by several different methods of inner region 26.Therefore, the reader can understand that each part mentioned above 40,44 and 48 only is as example.Desirablely be, in each part mentioned above 40,44 and 48, have at least a part at least 20% (percentage by vertical dimension is measured), be preferably at least 50%, be more preferably at least 100% surface, stable region that forms equal thickness.More particularly, form a kind of prism steady component of equal thickness in one or more in above-mentioned top 40, center section 44 and lower part 48, this prism steady component except that surrounding zone and Jing Qu except that have a series of continuous horizontal sections, and, stride across one section distance of at least 20% along the minimum dimension of top, center section and lower part that vertical meridian is measured.The meaning of above-mentioned term " equal thickness " is that above-mentioned continuous horizontal section thickness separately is roughly even, changes to be no more than 30 μ m or about 20%, with big being as the criterion of absolute value.In a particularly preferred structure, in upper, middle and lower each several part 40,44 and 48 at least two are more preferably and form the surface, stable region in whole 3.
The present invention relates to have contact lens and so-called " dynamic stability " contact lens of slow-roll stabilization mechanism, above-mentioned stabilizing mechanism comprises having for example prism cylinder stable region, stable region; The mechanism of periphery stable region.The contact lens that has the stable region has the surface profile of some protuberance, and eyelid just can make contact lens roughly relocate around its optical axis in the time of meeting this surface.Prism ballast have one be used in addition in lens region with the interactional wedge shape of eyelid in other words with the stable region of gradient, peripheral stable region then is positioned at outside the lens region.The dynamic stability contact lens contains upper and lower plane on eyeglass, and forms the interlude and the eyes interaction of a thickening, sees United States Patent (USP) NO.4095878.Persons skilled in the art also will appreciate that to also have the stabilizing mechanism of other these classes can advantageously be applied to the present invention.
Fig. 1 also illustrates many (promptly along level) representative section line A-A ', B-B ', C-C ', D-D ' and the E-E ' perpendicular to vertical meridian Z-Z ', and these sections are shown in Fig. 2, and the basic spherical curvature in each cross section has been shown among Fig. 2.The invention provides contact lens with the continuous horizontal section of containing the stable region that is shown in Fig. 2, the thickness in each cross section except that lens region 22 and surrounding zone 24 roughly evenly in other words about equally.For example, a cross section that has the stable region among Fig. 2 is D-D ' for example, and its thickness is roughly even, and in addition, the cross section that all that are shown in Fig. 2 have the stable region all has roughly homogeneous thickness except that lens region 22 and surrounding zone 24.
Desirablely be, thickness roughly uniformly the variation in thickness of each cross section in its cross section be no more than about 30 μ m or about 20%, with big being as the criterion of absolute value.In one embodiment, the variation in thickness in each cross section is not more than about 15 μ m or about 10%, for example is not more than about 10 μ m or about 7%, with big being as the criterion of absolute value.Above-mentioned variation in thickness will be understood that to be small enough to still can think that each cross section has the thickness of " roughly even ".
In exemplary embodiment of the present invention, contact lens 20 has a so-called prism ballast that is superimposed upon on the eyeglass in whole inner region 26.That is to say that in the intersection of contact lens bottom, thickness increases gradually from stable region periphery 34 two lines extremely identical in the intersection on contact lens 20 tops with vertical meridian Z-Z '.Fig. 3 illustrates above-mentioned thickness along the distribution on the vertical meridian with curve, and the right of figure illustrates the top 30 of surrounding zone 24, and the left side then illustrates the bottom 32 of surrounding zone 24.See the right side earlier, can see in the top 30 of surrounding zone 24 36 gradients to periphery 34 tops, stable region from the edge.In top 40, thickness is increased to horizontal cross-section line 42 gradually.Further increase by lens region 22 to horizontal line 46 above-mentioned thickness.48 bottoms to stable region periphery 34 have maximum thickness in the lower part.Eyeglass 36 has downward gradient again from stable region periphery 34 to lower limb in surrounding zone 24.
Therefore, it is corresponding to pass the prism ballast of all each several parts of top 40, center section 44 and lower part 48 in thickness distribution shown in Figure 3 and the contact lens 20.In fact, even also have above-mentioned prism ballast in lens region 22.Importantly, form prism ballast at least one in the uniform each several part 40,44 of horizontal section thickness and 48 of the present invention.Therefore, as shown in Figure 2, the cross section that all illustrates has homogeneous thickness along its width except that surrounding zone 24, certainly, since along the direction that is parallel to vertical meridian Z-Z ' from top to bottom thickness increase, so the thickness in each cross section is from section A-A ' increase to cross section E-E '.
The thickness of horizontal section evenly helps to make contact lens of the present invention stable, and these are different with previous contact lens.More particularly, contact lens of the present invention can be suitable for more wearer than the contact lens of prior art, and the structure of equal thickness torque that eyelid is acted on the eyeglass in other words is less because it has adopted uniform thickness.Above-mentioned equal thickness stable region structure owing to when nictation eyelid can upper and lower mobile eyeglass reach along each cross section of eyeglass all uniform contact, so can make eyelid that contact lens is had maximum interaction.Otherwise the contact lens of prior art in normal nictation process, when the interaction of the horizontal section of the eyeglass of eyelid and non-uniform thickness, can produce bigger torque.This is because contact lens will be positioned properly on eyes, eyeglass could be pressed into required orientation<general orientation so should have maximum eyeglass-eyelid interreaction force along eyeglass (promptly along each horizontal section)〉and the nictation<orientation of blinking the time fluctuation minimum.
The contact lens of prior art since maximum ga(u)ge peak value on each side of vertical meridian or put narrow, so more may form uneven eyeglass-eyelid interaction along the horizontal section.In addition, the horizontal range in the contact lens of prior art between the peak value of maximum ga(u)ge generally increases to horizontal central line from top, reduces to the lower part from horizontal central line then, and this makes the interreaction force between eyeglass-eyelid further change again.
Proved already that according to keeping the correct rotational orientation of contact lens in eyes, thickness uniform contact lens 20 in horizontal section of the present invention had more performance than other similar contact lens.Clinical testing shows that the specifically labelled position on eyeglass changes less from start to finish.For example, the situation of having studied one group of 20 people simultaneously is to measure the telltale mark position from start to finish on the various eyeglasses in the eyes, and measured the standard deviation of specifically labelled position, the result shows, the standard deviation of measuring of contact lens of the present invention this means that less than other contact lens contact lens of the present invention has higher rotational stability in eyes.
The topography generating writing pattern of Fig. 4 a has marked the thickness representative value of the contact lens 20 with thickness distribution shown in Figure 3.Understand that the contact lens shown in Fig. 4 a is roughly circular.In Fig. 4 a, inner region 26 is divided into a plurality of separate units by level with vertical grid line.Each level row's unit has homogeneous thickness in whole inner region 26.On the other hand, along the unit of vertical row, its thickness increases from top to bottom.For example, level row 50 its uniform thickness except that lens region is 150 μ m, and vertically to 52, the thickness on its top is 70 μ m, increases to 280 μ m downwards, and the bottom when just in time entering surrounding zone 24 begins again to reduce.One-tenth-value thickness 1/10 shown in Fig. 4 a is exemplary, and is applicable to soft hydrogel plaster ocular lens.Can be for the above-mentioned value of contact lens that other materials is made according to optical property or other performance changes of concrete material.
The reader can understand that the value of the separate unit that Fig. 4 a is drawn is represented the average thickness values in each unit.That is to say that the thickness of contact lens 20 gradually changes, do not have the border of step between the unit.More generally,, the application distinguishes various piece in other words though having described in the contact lens each,, these zones are shown only is for the present invention clearly is described.Persons skilled in the art can understand do not have marked difference between these zoness of different of contact lens, but merge smoothly mutually.
Fig. 4 a also illustrates contact lens 20, and 24 thickness reduces the variation of gradient in other words in the surrounding zone.For example, at the bottom mid point, reducing of thickness is 210-140-70 μ m successively, and this situation also can be seen on the curve of Fig. 3.Above-mentioned gradient in the surrounding zone 24 has formed along the so-called comfort zone at the edge of contact lens.Because thickness reduces, and helps eyelid and moves along contact lens.Specifically, have than the contact lens of macromutation with thickness on every side and compare the easier surrounding zone 24 that claimed to be with gradient of eyelid.
In one exemplary embodiment, contact lens 20 has the relation that cooperates with cornea that keeps eyeglass centering on cornea, the diameter of preferred contact lens is enough to topped whole cornea, and has best stability, so eyeglass can not become flexible, all stablize when staring and blink, this helps wearer's vision and comfortable.For the eyeglass-cornea matching relationship of the best, in the scope of the about 13.0~16.0mm of contact lens diameter, its sagitta of arc degree of depth (the recessed of rear curved surface gos deep into) is about 3.0~5.0mm.More suitably the contact lens diameter is 13.5~13.8mm.The suitable thickness at contact lens edge 36 is less than about 120 μ m, more suitably is about 90 μ m.In this respect, thickness is radially measured with respect to front curve.Edge 36 ragged edges can comprise the suitable rounding of lower limb corner.
Many meridian can be made in center by contact lens.In a preferred embodiment, feel the most comfortable in order to make the wearer, the radial thickness of eyeglass is less than about 250 μ m/mm from any meridianal rate of change along eyeglass at end to the edge 36 (just the surrounding zone 24) of stable region 34.For example, in the topography figure of Fig. 4 a, along the thickness change of any meridian in surrounding zone 24 less than 250 μ m/mm about.More suitably be, the thickness change in surrounding zone 24 less than 200 μ m/mm about.
Below further to illustrate the favourable interaction between surrounding zone 24 and the equal thickness district near every measurement of carrying out along eyeglass at lens edge 36 places of thickness point.For this principle is described, Fig. 7 illustrates by optical axis and since 3 o ' clock positions, and what do counterclockwise to move around eyeglass is each radial of unit with the degree.Certainly, because the thickness in the inner region 26 is equal, just corresponding with the thickness of the whole horizontal meridian of edge except that lens region along any meridianal point of maximum thickness.Therefore, the section start of inner region 26 and always be positioned on the stable region periphery 34 along any meridianal point of maximum thickness.But, owing to be provided with suitable stable region, change to some extent along the maximum ga(u)ge value of stable region periphery 34.
For the contact lens that has prism ballast of the present invention, along 225 ° meridian place, tube thickness is not how, and the distance between its point of maximum thickness (being stable region periphery 34) and the lens edge 36 all is not more than about 1.4mm.According to the present invention, for the contact lens that has the stable region of any kind, be about 200~400 μ m along its 225 ° of meridianal maximum ga(u)ges, more suitable 250~350 μ m that are about more suitably are about 320 μ m.Along 270 ° of meridians, also not tube thickness what, though the thickness about 320 μ m is suitable, the distance between its point of maximum thickness (for example the stable region periphery 34) and the lens edge 36 all is not more than 1.8mm.Band prism ballast for full mold pressing has eyeglass (just the front and back all is the eyeglass of mold pressing), its along the distance between 225 ° of meridianal point of maximum thickness (for example periphery 34 of stable region) and the neighboring 36 less than 1.8mm about, preferably, along 270 ° of meridians, the distance between its point of maximum thickness and the neighboring 36 less than 2.1mm about.In addition, along 180 ° of meridians, the distance between its inner region and the neighboring less than 1.3mm about.Generally speaking, the surrounding zone 24 of contact lens of the present invention is narrower than the contact lens that has the stable region of prior art, and as mentioned above, this also is because thickness is suitable, so the comfortable oblique angle in surrounding zone 24 is less.
Though preferred contact lens of the present invention seamlessly transits between its different part, do not get rid of and have independently border or corner.For example, the transition between its surrounding zone 24 and the inner region 26 can be formed by corner that is positioned at the rounding on the stable region periphery 34 or discontinuous transition.Fig. 3 b illustrates along the example of the transition between the meridianal stable region 26 of Z-Z ' and surrounding zone 24 (promptly at 34 places).
Fig. 5 a~5d illustrates several remodeling of contact lens of the present invention, and these remodeling contact lens form different ballast portion respectively in the stable region.For convenient illustrations, ask the reader return referring among Fig. 1 to the explanation of the definition of the various piece (being top, center section and lower part) of inner region 26.Contact lens 70 shown in Fig. 5 a has the ballast portion 72 in the top that is arranged on inner region, and inner region is between lens region 74 and surrounding zone 76.Contact lens of the present invention 80 shown in Fig. 5 b has the top that is arranged on inner region and the ballast portion 82 of center section.Contact lens 90 shown in Fig. 5 c has and is arranged on whole inner region, i.e. ballast portion 92 by its top, center section and lower part.At last, the contact lens shown in Fig. 5 d 100 has the ballast portion 102 of the lower part that only is arranged on inner region.
Other unshowned remodeling comprise whole at inner region center section or lower part or in the center section except top and lower part two parts, form ballast portion.In addition, in a kind of so-called " peripheral stable region " structure, ballast portion surrounds lens region, and perhaps in the structure of a kind of so-called " prism ballast ", ballast portion is passed through lens region continuously.
Fig. 6 a~6d illustrates multiple other contact lens of the present invention, and they have the cylinder correction district that is positioned at its front.More particularly, the direction of its axis 112 that rotates along the upper and lower axis with respect to eyeglass in each contact lens is provided with toric lens district 110.Therefore obviously need suitable stable region be set to keep the suitable offset orientation of long axis 112 to eyeglass.
Fig. 6 a illustrates has the top continuous contact lens 120 of the ballast portion 122 by center section and lower part then that originates in inner region.Fig. 6 b illustrates the contact lens 130 of the ballast portion 132 with whole lower part that is positioned at inner region.Fig. 6 c illustrates the contact lens 140 of the ballast portion 142 with whole center section that is positioned at inner region.At last, Fig. 6 d illustrates the contact lens 150 of the ballast portion 152 with the top that only is positioned at inner region.
Fig. 8 illustrates the contact lens with prism ballast (CooperVi soaFrequency Xcel (Encore) Toric) of prior art, and the line of the transition between each district of sign draws among the figure.Specifically, with the interior lines 204 that are roughly figure stable region 202 and lens region 200 are separated, and 26 tell stable region 202 from the surrounding zone by being roughly circular outside line 208, though interior lines 204 preferably roughly fixed on optical axis 0A, but outside line 208 is but along upwards skew of vertical meridian 210.The result is, and is wideer than the lower part in the stable region 202 on top.Specifically, significantly greater than the radial width B of bottom, in fact, the twice that top radial width A can be bottom radial width B is many for the top radial width A of stable region 202.
Otherwise as shown in Figure 1, the inner region 26 of contact lens of the present invention is roughly circular, and its radial width A is about below 300% of radial width B.In other words, for the eyeglass of the band prism ballast of mold pressing, its stable region is annular, and keeps following relation: 0.33≤B≤A, and in addition, for the contact lens of all band prism ballast, its annulus scope keeps following relation: 0.55≤B≤A.
Obviously, available eyeglass with different focal powers is implemented the present invention, and for example, the focal power of contact lens of the present invention can be about-8~+ 8 diopters, also not necessarily is confined to this scope certainly.
In addition, contact lens of the present invention also can have other stabilization characteristics except the stable region structure of above-mentioned uniform thickness.For example, the surrounding zone can have the zone of flattening that is used for dynamic stability, and a kind of stabilization characteristics of peripheral stable region perhaps can be set in the central lens region outside of eyeglass.
Though with regard to each concrete example and embodiment the present invention has been described in the above, should be understood that the present invention is not limited to these, but can in the following claims scope, implement the present invention with various methods.