Summary of the invention
The object of the present invention is to provide a kind of method of designing ophthalmic progressive additional lens of the demand that goes for different lens wearer.
The objective of the invention is to realize by following technical solution: a kind of method of utilizing the meridian designing ophthalmic progressive additional lens is characterized in that: include following steps:
A) designing ophthalmic progressive additional lens meridian diopter change curve:
According to the requirement of eyeglass wearer personalized design, determine eyeglass look far point and look the near point position, look the far point diopter, eyeglass adds parameters such as luminosity, determines ophthalmic progressive additional lens meridian diopter change curve according to following equation then:
R in the formula
DFor looking far point P
DThe radius-of-curvature at place;
r
RFor looking near point P
RThe radius-of-curvature at place;
R (u) is apart from the radius-of-curvature of center O point apart from the u place on the meridian;
L is for looking far point P
DDistance apart from center O point;
M is P
DFirst non-zero of some u=-L place
Exponent number;
L is P
RFirst non-zero of some u=h-L place
Exponent number;
c
nBy equation
Find the solution and get;
H is P
DTo P
RBetween distance.
B) determine ophthalmic progressive additional lens surface face shape:
At first select outline line form with ophthalmic progressive additional lens meridian diopter change curve quadrature, curvature equates with orthogonal points place curvature on the outline line, outline line can be straight line, para-curve or hyperbolic curve, also can be respectively to look far point and to look circle or the ellipse that near point is the center;
Calculate each point rise on the eyeglass according to the infinitesimal geometry primitive rule then;
After the each point rise is tried to achieve on the eyeglass, try to achieve minimum and maximum radius of curvature R according to following equation
1And R
2:
(rt-s
2)R
2+g[2pqs-(1+p
2)t-(1+q
2)r]R+g
4=0
In the formula:
X, y, z are the value of each point rise;
Try to achieve maximum, minimum profile curvature radius R
1And R
2After, basis again
Calculate each point average sphere degree, according to
Calculate the astigmatism of each point, thereby determine lens surface face shape.
Further, described outline line is a hyperbolic curve, and the rise of each point is passed through the infinitesimal geometry equation on the eyeglass:
Calculate and get;
In the formula (ξ, η ζ) are each position center of curvature coordinate of sphere, wherein:
ξ(u)=u-r(u)sinθ(u),
η(u)=0,
R (u) is apart from the radius-of-curvature of center O point apart from the u place on the meridian.
The present invention has following advantage:
1. the present invention is according to wearer's vision requirement, and design distributes along the meridianal diopter of progressive multi-focus lens.Therefore, the present invention can be used for multi-purpose progressive multi-focus lens design.
2. according to meridian diopter change curve, determine ophthalmic progressive additional lens surface face shape, progressive multi-focus lens diopter and astigmatism distribution more become to satisfying wearer's demand.
Embodiment
A kind of embodiment that utilizes the method for meridian designing ophthalmic progressive additional lens of the present invention includes following steps:
C) designing ophthalmic progressive additional lens meridian diopter change curve:
According to the requirement of eyeglass wearer personalized design, determine eyeglass look far point and look the near point position, look the far point diopter, eyeglass adds parameters such as luminosity, contrast Fig. 2 then and determine ophthalmic progressive additional lens meridian diopter change curve (this curve map is as shown in Figure 3) according to following equation:
R in the formula
DFor looking far point P
DThe radius-of-curvature at place;
r
RFor looking near point P
RThe radius-of-curvature at place;
R (u) is that meridian MM ' goes up apart from the radius-of-curvature of center O point apart from the u place;
L is for looking far point P
DDistance apart from center O point
M is P
DFirst non-zero of some u=-L place
Exponent number;
L is P
RFirst non-zero of some u=h-L place
Exponent number;
c
nBy equation
Find the solution and get;
H is P
DTo P
RBetween distance.
D) determine ophthalmic progressive additional lens surface face shape:
At first select outline line form with ophthalmic progressive additional lens meridian diopter change curve quadrature, curvature equates with orthogonal points place curvature on the outline line, outline line can be straight line, para-curve or hyperbolic curve, also can be respectively to look far point and to look circle or the ellipse that near point is the center; In the present embodiment, outline line is elected hyperbolic curve as, at first calculates the curvature of each point on the eyeglass by outline line, then on the eyeglass each point rise according to the infinitesimal geometry primitive rule:
Calculate and get;
In the formula (ξ, η ζ) are each position center of curvature coordinate of sphere, wherein:
ξ(u)=u-r(u)sinθ(u),
η(u)=0,
R (u) is apart from the radius-of-curvature of center O point apart from the u place on the meridian.
After the each point rise is tried to achieve on the eyeglass, try to achieve minimum and maximum radius of curvature R according to following equation
1And R
2:
(rt-s
2)R
2+g[2pqs-(1+p
2)t-(1+q
2)r]R+g
4=0
In the formula:
X, y, z are the value of each point rise;
Try to achieve maximum, minimum profile curvature radius R
1And R
2After, basis again
Calculate each point average sphere degree, according to
Calculate the astigmatism of each point, thereby determine lens surface face shape.
Among the present invention,,, can design ophthalmic progressive additional lens with different astigmatisms and sterad by to the m selection different in the meridian diopter change curve equation with the l value according to different wearers' different demands.
Among the present invention, when selecting the contour curve of other form for use, each position center of curvature coordinate Calculation mode of sphere is the same, but the position of the center of curvature changes to some extent, and as for specifically choosing any contour curve, then will be according to wearer's real needs.
Generally speaking, according to method provided by the invention, can carry out the correspondence design easily, to satisfy wearer's demand better according to different wearers' various demands.
The eyeglass of the method according to this invention design can be made with any known material that is suitable for use as lens, and is obtainable on these materials or the market, or its manufacture method is known.And, can adopt the method for manufacturing lens of any routine according to the manufacturing of eyeglass of the present invention, include but not limited to grinding, full wafer casting, pressing mold, thermoformed, lamination, surface casting or their combination.Preferably, in the manufacturing of two progressive eyeglasses, the wherein one side of eyeglass is by forming progressive of a lens blank top casting, and in addition one side by being processed to form.
To further specify the present invention, this example does not constitute any restriction to the present invention below by example.
Example one: default ophthalmic progressive additional lens is looked the far point eyeglass number of degrees 100 degree, look far away with look to add the luminosity number between the near point be 150 to spend, eyeglass passage length h=21 millimeter is looked the spacing L=7 millimeter of far point A and center of lens point.Optic diameter 60mm, refractive index 1.499.
Fig. 5 and Fig. 6 are respectively ophthalmic progressive additional lens average sphere degree figure and ophthalmic progressive additional lens astigmatism distribution figure in the embodiment of the invention one.By the curve map of Fig. 3 as can be known, keep constant substantially along eyeglass meridian direction diopter looking the far field, rise to the near reading range diopter and increase gradually by looking far point, the meridian that diopter changes with design matches, and astigmatism is all very little with distortion.
Example two: adopt example one described lens parameters, adopt meridian diopter curve such as accompanying drawing 7, this curve also calculates according to above-mentioned meridian diopter change curve equation and gets, but it is different in m value and l value value and the example one, therefore its meridian diopter curve map is also different, looking far point and looking meridianal diopter is almost linear change between the near point, look far point and looking outside the near point slowly value of tending towards stability of diopter, looking outside the far point value of tending towards stability more slowly, and dioptric optical value is less, then is tending towards a less dioptric optical value after looking near point quickly.
Fig. 9 and Figure 10 are respectively ophthalmic progressive additional lens average sphere degree figure and ophthalmic progressive additional lens astigmatism distribution figure in the embodiment of the invention two.
By example one and example two as seen, although the design parameter of eyeglass is the same, different meridian diopters distributes, and the sterad of eyeglass and astigmatism distribution form difference are very big.Example one meridian diopter changes suddenly, the eyeglass that designs have open have same diopter, astigmatism little look the far field.Example two meridian diopters change milder, and the eyeglass that designs does not have the open same dioptric far field of looking that has, and are looking average sphere degree decline in addition outside the far point; It is less that it only looks near the far point in a small range astigmatism.Two examples are compared, and the eyeglass that is designed by example two meridians has the passage of broad and the openr near reading range that sterad is stable, astigmatism is little, and the astigmatism of its both sides is also less.
This shows, if the diopter on the meridian remains unchanged in looking the long distance in far field, stretch to eyeglass below along meridian and to change and to change fast design again suddenly, can design that to look the far field open but progressive multi-focus lens that the both sides astigmatism is bigger is applicable to that looking far is that main taking into account looked nearly use; If it is slower that the diopter on the meridian changes, can in a segment distance of looking closely and look the far field, keep stable dioptric optical value again, the eyeglass of its design has suitable substantially the looking near and look the far field of open degree, and the both sides astigmatism is less, closely takes into account in being applicable to help and looks use.
Though in conjunction with the accompanying drawings the embodiment of the invention has been done detailed description; it only is embodiments of the present invention that but those skilled in the art should be understood that above embodiment; and be not qualification to protection scope of the present invention, any improvement of doing based on invention of the present invention is all naturally in protection domain of the present invention.