Arizona眼睛模型

UA}k"uM   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。 xEGI'lt   jh9^5"vQ   模型 QO0T<V   }56"4/ Z   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。 H=EvT'g   Table 1. AZ眼睛模型的定义 j&ddpS(s   EY':m_7W   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. IeE+h-3p   ]x! vPIyq   光源 amOBUD5Ld`   8\/E/o3   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。 R|`}z"4C   zkB_$=sbn#   图1. 光源和提示信息使用 ACc.&,!IZ   PoQ@9 A   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。 VMsAT3^w   KD=T04v   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。 s+9q:   图2. 字母F光源的设定方法光 o1QK@@}   19h8p>Sx0   图3. 字母F在视网膜上位置点列图 ,:j^EDCsaJ   [p|-G*=00   视网膜的散射 FX 0 ^I 0   7'd_]e-.   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。 ++BVn[1   XV]`?   图4. 视网膜朗伯散射设定 =]E;wWC   mbU[fHyV   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。 DO(FG-R   s9zdg"c'   图5. 视网膜重点采样规格设定 USfOc   PKty'} KF   脚本 -(@dMY   /\(0@To   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： 3L/>=I{5   图6. 用户对话框的创建与编辑 aa8WRf   图7. 用户对话框编辑器 =&< s*-l[   .^fq$7Y}7   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。 77.5 _   余下的脚本计算与屈光度有关的所有参数。 +UB+. 5 P   M n3cIGL   分析 [-=PK\ B   lmgMR|v   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 _\1wLcFj   图7. 字母F在视网膜上颜色分析 n@Y`g{{e~   %Hp TQ    脚本代码 ;a* i*{\Rm   J+kxb"#d   Option Explicit     'Remove this to enable non-dimensioned variables to be used. 1ki##v[ W8   QB7E:g&7   Dim entity As T_ENTITY ?yU|;my   Dim op As T_OPERATION /|bir6Y:   Dim mat As T_MODELMATERIAL >x eKO2o   Dim A As Double L Lm{:T7   Dim pupilDiam As Double |JtdCP{   Dim eID As Long :OUNZDL   Dim parID As Long X)$3sTj   Dim count As Integer ~ucOQVmz@   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double >| r ID   Dim tlens As Double, nlens As Double }b\e2ZK   Dim curv As Double, conic As Double Y, )'0O   Dim ok As Long y9?BvPp+   2X&~!%-   Sub Main JnlM0jc]`   jxm.x[1ki^       '用户输入对话框 -:h5Ky"       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 r=~yUT           TextBox 220,21,40,21,.TextBox1 'default: 0 !=_:*U)-'           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 =\eM -"r           OKButton 40,91,90,21 kS%FV;9>(           CancelButton 190,91,90,21 G!C2[:[g           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 u`xmF/jhQ           TextBox 220,49,40,21,.TextBox2 'default: 4 !vHnMY~AG       End Dialog yNoJrA       Dim dlg As UserDialog pn{Mj   Zm>Q-7r9       ok = Dialog (dlg) U@@#f;&   s7A{<>:       If ok=0 Then    'cancel button was pressed be|k"s|6)           Print "Execution cancelled." MS)#S&           End h/?8F^C#v       End If 47ppyh6@   rbHrG<+7zO       'Assign accommodation and pupil diameter & use defaults if field left empty vRpMZ)e       If dlg.TextBox1 = "" Then I3uaEv7OZc           A = 0           'Default accommodation %M2.h;9]*\       Else mnzamp           A = CDbl(dlg.TextBox1) Cg |_) _w       End If $W<H[k&(B   FVW<F(g`       If dlg.TextBox2 = "" Then Ol`/r@s           pupilDiam = 4   'Default pupil diameter >0k7#q}O       Else y\$ B9KX           pupilDiam = CDbl(dlg.TextBox2) Z3<>Z\6D       End If `Rub"zM   D}XyT/8G3       Print " " R ]VY PNns       Print "Accommodation = " & A & " Diopters" 16_HO%v->       Print "Pupil Diameter = " & pupilDiam & " mm" LYhgBG,   q(M[ij       ' Calculate new parameters with accommodation pk%I98! Jy       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness !@{_Qt1   T^B&GgW       Rant = 12.0 - 0.4*A                     'Radius of anterior lens 8  k9(iS       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens  kj~)#KDN   (cAv :EKpo       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens LY'_U0y4       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens p%EU,:I6   7h?PVobe       tlens = 3.767 + 0.04*A                  'Lens thickness b#(SDNo6   RIJ+]uir4       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Y5&Jgn.l    {9vvj       'Adjust parameters to account for accommodation I&l1b>   aR6?+`6<       '************************************************************************* y8HLrBTza       'Aqueous thickness (Position of Lens) \[Op:^S       '************************************************************************* _v{,vLH       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^N#kW-i       GetCustomElement eID, entity ;2q;RT`h   /6B!&b2f       parID = FindFullName( "Geometry.Arizona Eye" ) "(PJh\S>S   5gARGA       ' Delete any shift(s) in z WCA`34(       count = 0 !f-mC,d       While GetOperationCount(eID)>count }`&#{>]2           GetOperation eID, count, op &&4av*\I           If op.Type="ShiftZ" Then oe_l:Y%               DeleteOperation eID,count M;OY+|uA               count=count-1 x.qn$?3V]           End If %Js3Y9AL C           count=count+1 ;29q       Wend ;ZPAnd:pb   o\vIYQ        'Set new shift in Un@B D}@\       op.Type = "ShiftZ" %Ez%pT0TQ#       op.val1 = taq e.hHpjWi?Z       op.parent = parID an={h,       AddOperation eID, op !;.i#c_u       Print "Set aqueous humor thickness = " & taq-0.55 xfCq;?MupW   hAi50q;z       '*************************************************************************  /s.sW l       'Radius and conic constant of anterior lens dFD0l?0N       '************************************************************************* hPF9y@lh       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) $]|fjB#D       GetConic eID, entity, curv, conic A]`63@-.   6pDb5@QjTy       SetConic eID, entity, 1/Rant, CCant hu%rp{m^,       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant \2 &)b   _?#}@?       '************************************************************************* |UZPn>F~       'Radius and conic constant of posterior lens ,+<NP}Yg#G       '************************************************************************* YdX#`       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) o7S,W?;=5       GetConic eID, entity, curv, conic 8`XpcK-0   +C1/02ZJ       SetConic eID, entity, 1/Rpost, CCpost ^]o]'       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost b<};"H0a   (.4mX t       '************************************************************************* +Rn]6}5m\       'Lens thickness (Position of posterior lens surface) c7X5sMM,       '************************************************************************* +:pjQ1LsJ   qFp }+ s       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) r7o63]   8X!^ 2B}J       ' Delete any z-shift(s) eE5U|y)_       count = 0 hd1(q33       While GetOperationCount(eID)>count "f/lm 2<           GetOperation eID, count, op [}q6bXM*           If op.Type="ShiftZ" Then W}#eQ|oCV               DeleteOperation eID,count }md[hiJ               count=count-1 uq~$HXd c           End If &+;z`A'|8           count=count+1 +F$c_ \>       Wend 4<fKB&   ku3Vr\s       'Set new z-shift *>,8+S33r{       op.Type = "ShiftZ" ;4p_lw@       op.val1 = tlens 8sjAr.iT.       op.parent = parID I!3qb-.Q       AddOperation eID, op 'MH WNPG0       Print "Set lens thickness = " & tlens iV;X``S   {eA0I\c(C       '************************************************************************* kaf4GME]       'Lens index of refraction SVWtKc<       '************************************************************************* !PJD+SrG       eID = FindMaterial( "Lens" ) :"5'l>la       GetModelMaterial eID, mat k44sV.G4L   C1_':-4       mat.Nd = nlens k"X<gA       SetModelMaterial eID, mat b$\3Y'":       Print "Set lens index of refraction = " & nlens 5:v"^"Sz   E+-ahvk       '************************************************************************* %_C!3kKv~       'Pupil diameter GyQu?`       '************************************************************************* 78&(>8@m       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 6qg_&woJ3   l2Z!;Wm(       'Adjust pupil diameter (trimming volume inner hole) 6cH.s+   fvnj:3RK       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" uz-O%R-   mTXeIng?       ' Adjust pupil location to just in front of the lens |^p7:)cy       parID = FindFullName( "Geometry.Arizona Eye" ) >8h14uCk       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) >__t 2       count = 0 )Zud|%L       While GetOperationCount(eID)>count j6<o,0P           GetOperation eID, count, op 5Y77g[AX2-           If op.Type="ShiftZ" Then Ca}T)]//               DeleteOperation eID,count /NRdBN               count=count-1  ;LEO+,6           End If 8U}BSM_<2           count=count+1 1KwUp0%&       Wend A'Q=DoE       op.Type = "ShiftZ" ?t<yk(q       op.val1 = taq-0.01 %%`Q5I       op.parent = parID &("HH"!       AddOperation eID, op %6Wv-:LY   AmYqrmJ       Print "Set pupil diameter = " & pupilDiam TY,5]*86I&   O#Y;s;)i"       'Update AZ Eye subassembly Description @BCws)       eID = FindFullName( "Geometry.Arizona Eye" ) ~2 aR>R_nT       GetEntity eID, entity e(nT2E       entity.Description = "Accommodation = " & A & "D" ^APPWQUl       SetEntity eID, entity w0W9N%f#=   nO-1^HUl       Update '?7? "v       Print "DONE!" Qb "\j        +M@p)pyu   End Sub xZ2^lsY   ,au-g)IFZ   如果屈光度是4，光瞳直径是4，则会输出如下数据： ]M2<b:yo   YT:])[gVV   Accommodation = 4 Diopters g Mhn\   Pupil Diameter = 4 mm \X&LrneR"t   Set aqueous humor thickness = 2.81 ^\|Hz\"*   Set anterior lens radius = 10.4 and conic constant = -2.375869 [fVtQ@-S!   Set posterior lens radius = -4.424557 and conic constant = -3.081019 & !0[T    Set lens thickness = 3.927 X{2))t%   Set lens index of refraction = 1.42672 _g{*;?mS   Set pupil diameter = 4  QN!.~>   DONE!

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