Arizona眼睛模型

?<Mx*l   人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 ;Qc^xIPy   \,lIPA/L   模型 @ V^5_K   LIyb+rH#yg   模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 k _gl$`A   Table 1. AZ眼睛模型的定义 <B @z>V   vM:c70=   在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. qT#NS&T!-   7>AMzNj   光源 i#*lK7   pP#|: %   多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 rQ&XHG>Q*   J(P'!#z^   图1. 光源和提示信息使用 5%@~"YCo   ,VzbKx,   除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 >?ec"P%vS/   ]AN%#1++U   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 5Ux=5a   图2. 字母F光源的设定方法光 ogJ';i/o   Wy /5Qw~s   图3. 字母F在视网膜上位置点列图 h&~9?B   ~b4kV)[ q   视网膜的散射 ^a1k"|E?f   ]a[2QQ+g   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 UoSc<h|   <5G4|l   图4. 视网膜朗伯散射设定 OAgZeK$   <KI>:@|Sc   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 ^}J,;Zhu5   z>'vS+axV   图5. 视网膜重点采样规格设定 bwJluJ,E   d vo|9>   脚本 ^E~1%Md.   S5YEz XG   内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： ,v?FR }v   图6. 用户对话框的创建与编辑 SQMtR2   图7. 用户对话框编辑器 Zt9ld=T   T#vY(d   如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 :z%Zur+n c   余下的脚本计算与屈光度有关的所有参数。 u EERNo&   2av=W   分析 }U%T6~_wR   Mh{;1$j#   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 sI{?4k   图7. 字母F在视网膜上颜色分析 JEP9!y9y   [lu+"V,<LJ   脚本代码 rMw$T=Oi   UXwI?2L   Option Explicit     'Remove this to enable non-dimensioned variables to be used. D<WGau2H   H;ujB \+   Dim entity As T_ENTITY m8+ EMBl   Dim op As T_OPERATION A-rj: k!   Dim mat As T_MODELMATERIAL ][XCpJ)8   Dim A As Double 0;]VTz?P   Dim pupilDiam As Double Y@ vC!C   Dim eID As Long @xk;]H80   Dim parID As Long mXyg\5   Dim count As Integer j9-.bGtm?.   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double H.o3d/8:   Dim tlens As Double, nlens As Double 4ti,R'   Dim curv As Double, conic As Double 7;Vmbt9   Dim ok As Long kUr/*an   _94R8?\_V7   Sub Main +k0UVZZX?   |;I"Oc.w^R       '用户输入对话框 "{c@}~       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Ylgr]?Db*           TextBox 220,21,40,21,.TextBox1 'default: 0 W*,$0 t           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 #F6M<V'           OKButton 40,91,90,21 Pu'NSNT           CancelButton 190,91,90,21 &2n5m&           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 u(PUbxJ V           TextBox 220,49,40,21,.TextBox2 'default: 4 WmRu3O       End Dialog s{42_O?,c       Dim dlg As UserDialog by$mD_sr   g!)*CP#;       ok = Dialog (dlg) iP1yy5T   |3hNTH?       If ok=0 Then    'cancel button was pressed m6Qm }""           Print "Execution cancelled." Qv )DSl           End 57_AJT hR       End If  RcZ&/MY   <~u-zaN<W       'Assign accommodation and pupil diameter & use defaults if field left empty Jyp7+M]       If dlg.TextBox1 = "" Then Sw>,Q-32           A = 0           'Default accommodation hZ')<@hNP       Else >LB*5           A = CDbl(dlg.TextBox1) dqi31e{*2\       End If J<&?Hb*|   6=*n$l#}       If dlg.TextBox2 = "" Then &z>iqm"Ww           pupilDiam = 4   'Default pupil diameter gf^y3F[\       Else  "Id1H           pupilDiam = CDbl(dlg.TextBox2) ke)<E98DC       End If Zm+GH^f'   o@L '|#e       Print " " JZJb&q){       Print "Accommodation = " & A & " Diopters" JM53sx4&       Print "Pupil Diameter = " & pupilDiam & " mm" *@WBaN+   UlPGB2B       ' Calculate new parameters with accommodation hdqr~9       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness F'@9kdp   U}l=1B       Rant = 12.0 - 0.4*A                     'Radius of anterior lens Sae*VvT6       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens is^5TL%@   k4` %.;       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens /!60oV4p0       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens <<-BQ l~   6p.y/LMO       tlens = 3.767 + 0.04*A                  'Lens thickness 29&F_   .sb0|3&       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction lk=[Xo   =6=l.qyYK       'Adjust parameters to account for accommodation (@=h(u.   UgOhx-8       '************************************************************************* vorb?iVf>       'Aqueous thickness (Position of Lens) Dw,LB>Eq,       '************************************************************************* sX Y{g0%       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) H)Z$j&S{       GetCustomElement eID, entity m]}EVa_I`/   .Vs|&c2im       parID = FindFullName( "Geometry.Arizona Eye" ) w,X J8+B   7U Uu1"|a|       ' Delete any shift(s) in z Vygh|UEo       count = 0 ;Q[E>j?w=       While GetOperationCount(eID)>count j|b$b,rF\           GetOperation eID, count, op TZdJq           If op.Type="ShiftZ" Then fe}RmnAC               DeleteOperation eID,count kc2 8Q2               count=count-1 ^__P;Gr`           End If -.-@|*5           count=count+1 Q v},X~^R       Wend g O8~$Aj    vF'IK,       'Set new shift in xX8c>p       op.Type = "ShiftZ" ppeF,Q       op.val1 = taq 7}(YCZny5       op.parent = parID 'G`xD3 E3,       AddOperation eID, op Q _*.1L       Print "Set aqueous humor thickness = " & taq-0.55 _Ecs{'k   dE3M        '************************************************************************* `*]r+J2       'Radius and conic constant of anterior lens "po;[ Ia2       '************************************************************************* 8 v da"       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) cu#r#0U-       GetConic eID, entity, curv, conic e|^.N[W   oMNBK/X_       SetConic eID, entity, 1/Rant, CCant ;h#Q!M&e#       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant J@rBrKC   CU/Id`"tW       '************************************************************************* m=w #l>!       'Radius and conic constant of posterior lens zJOyr"B'8       '************************************************************************* ^xr &E       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) I~-sBMm(w       GetConic eID, entity, curv, conic .{(gku>g(   -y/Y%]%0       SetConic eID, entity, 1/Rpost, CCpost >&T J       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 4OG1_6K   yXf+dMv        '************************************************************************* 8boiJku`       'Lens thickness (Position of posterior lens surface) :aD_>,n       '************************************************************************* (T.j3@Ko   SN$3cg]z       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~Yre(8+M   6?/f$,v       ' Delete any z-shift(s) v}@Uc-(       count = 0 K) eyFc       While GetOperationCount(eID)>count D$`$4mX@hP           GetOperation eID, count, op Io('kCOR;           If op.Type="ShiftZ" Then S=$ \S9               DeleteOperation eID,count 2l~qzT-               count=count-1 V\AF%=6}           End If `U>]*D68           count=count+1 "rpP       Wend )0=H)k0   <V|\yH9       'Set new z-shift {Ut,x i       op.Type = "ShiftZ" l_ LH!Tu       op.val1 = tlens ) gxN'z       op.parent = parID IYhn*       AddOperation eID, op -R`nitf       Print "Set lens thickness = " & tlens ?VyiR40-Cx   [6nN]U~Y       '************************************************************************* GvL\%0Ibx       'Lens index of refraction +0:]KG!Zs.       '************************************************************************* 0aYoc-( A       eID = FindMaterial( "Lens" ) u>V~:q\X       GetModelMaterial eID, mat 4u1au1c   :=K+~?       mat.Nd = nlens JE;!~=       SetModelMaterial eID, mat Z_Y gV:jc       Print "Set lens index of refraction = " & nlens L; <Pod   +,eF(VS!       '************************************************************************* )ZfbM|       'Pupil diameter r$,Xv+}       '************************************************************************* Pe@*')o*       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) \CYKj_c   q oz[x       'Adjust pupil diameter (trimming volume inner hole) rW*[sLl3   nDz.61$[       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" X6r3$2!   m wF{z.t"       ' Adjust pupil location to just in front of the lens 6N/6WrQEeg       parID = FindFullName( "Geometry.Arizona Eye" ) y`pgJO       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ?p>m;Aq       count = 0 5W09>C>OC       While GetOperationCount(eID)>count H9[0-Ur5           GetOperation eID, count, op zo1fUsK?           If op.Type="ShiftZ" Then 1#|qT7               DeleteOperation eID,count } ;d=               count=count-1 0 .ck!"h}           End If :{aiw?1           count=count+1 :VX2&*       Wend (b7',:_U7       op.Type = "ShiftZ" Po\d!       op.val1 = taq-0.01 CZkmd       op.parent = parID PD-*rG `       AddOperation eID, op WFvVu3   wjHH%y       Print "Set pupil diameter = " & pupilDiam d}@n,3   m=60a@o]       'Update AZ Eye subassembly Description HHT8_c'CC#       eID = FindFullName( "Geometry.Arizona Eye" ) Ru$%gh>v       GetEntity eID, entity =RHIB1       entity.Description = "Accommodation = " & A & "D" , Q )       SetEntity eID, entity Axla@   9dva]$^:*1       Update $NBQv6#:       Print "DONE!" CxrsP.        $?DEO[p.   End Sub NOl/y@#   3.h0   如果屈光度是4，光瞳直径是4，则会输出如下数据： >oapw5~5   /#[mV(k   Accommodation = 4 Diopters @u: q#b   Pupil Diameter = 4 mm _lfS"ae   Set aqueous humor thickness = 2.81 jM>;l6l   Set anterior lens radius = 10.4 and conic constant = -2.375869 -(zw80@&   Set posterior lens radius = -4.424557 and conic constant = -3.081019 8`Tj*7Y=   Set lens thickness = 3.927 _D8:p>=   Set lens index of refraction = 1.42672 O]t)`+%q   Set pupil diameter = 4 5m?9O7Pg   DONE!

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