Arizona眼睛模型

2WYPO"q   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。 Aj]V`B:65   'K,:j 388   模型 ."y1_dDql   by/jYg)+   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。 Y,zxbXZv'5   Table 1. AZ眼睛模型的定义 K0Fh%Y4)QH   l0A&9g*l2   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. \d$!a5LF}   _b;{_g   光源 /FEVmH?   aPbE;" f   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。 I"7u2"@-8j   ,{?%m6.lE   图1. 光源和提示信息使用 h2;F   7o5BXF   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。 _~iw[*#u   $[=%R`~w   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。 ]}2ZttQ?   图2. 字母F光源的设定方法光 Otm0(+YB7    t[ C/   图3. 字母F在视网膜上位置点列图 _[ZO p ~   LOV)3{m   视网膜的散射 zu|\fP   s(q_ o   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。 t"/q]G5   M}v/tRI   图4. 视网膜朗伯散射设定 =^50FI|   agW@{c   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。 AoL2@C.C%D   +@iA; 2&   图5. 视网膜重点采样规格设定 ur7q [n   )iK6:s#   脚本 H-fX(9   um>6z_"   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： ,>+p-M8ZL   图6. 用户对话框的创建与编辑 Q9G;V]./   图7. 用户对话框编辑器 FZE"7ec>m   mk+B9?;cF-   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。 ?|B&M\}g   余下的脚本计算与屈光度有关的所有参数。 N7 $I^?<   2Gaa(rJ5o   分析 JKGe"   T\>a!   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 'o>B'$   图7. 字母F在视网膜上颜色分析 i5?q,_   &t:Gx<]   脚本代码 6-B|Y3)B   :\7X}n *&   Option Explicit     'Remove this to enable non-dimensioned variables to be used. vJOw]cwq   (7=!+'T"   Dim entity As T_ENTITY o:P}Wg/NK   Dim op As T_OPERATION Hm'=aff6A   Dim mat As T_MODELMATERIAL 6 EC*   Dim A As Double 3/W'V,5G6   Dim pupilDiam As Double Opc ZU{4b   Dim eID As Long 0-yp,G   Dim parID As Long z]`k#O%%)   Dim count As Integer ktBj|-'>   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double !sW(wAy?o   Dim tlens As Double, nlens As Double  ^J)mH[   Dim curv As Double, conic As Double $jqq `n_   Dim ok As Long fbKkq.w   8=uu8-l8g   Sub Main 6){]1h"   ?FF4zI~       '用户输入对话框 9}F*P669f       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 [dIXR           TextBox 220,21,40,21,.TextBox1 'default: 0 x&Kh>PVh\           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 w\i\Wp,FP           OKButton 40,91,90,21 E Z$>.iy{           CancelButton 190,91,90,21 22M1j5           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 A5R<p+t6           TextBox 220,49,40,21,.TextBox2 'default: 4 K <qk.~ S       End Dialog OJ5#4qJ[       Dim dlg As UserDialog sjwo/+2   F{~{Lthc       ok = Dialog (dlg) ,*hLFaR-   ![_*(8v}S       If ok=0 Then    'cancel button was pressed KZ ;k)O.Ov           Print "Execution cancelled." N&g3t%F           End "(z5{z ?S       End If 6GSI"M6s   mmEYup(l0;       'Assign accommodation and pupil diameter & use defaults if field left empty 7k9G(i[-+       If dlg.TextBox1 = "" Then RcM/!,B           A = 0           'Default accommodation [~#WG/!:       Else *|C^=*j9           A = CDbl(dlg.TextBox1) }v!$dr,j'       End If QaS7z#/?.   B43HNs       If dlg.TextBox2 = "" Then W=Mb           pupilDiam = 4   'Default pupil diameter {kCw+eXn?       Else pg.ri64H<           pupilDiam = CDbl(dlg.TextBox2)  J^ }V|#       End If (SDr!!V<   `YLD`(\       Print " " Q$1bWUS&       Print "Accommodation = " & A & " Diopters" 8WbgSY`       Print "Pupil Diameter = " & pupilDiam & " mm" Vp*KfS]   SmdjyK1~8       ' Calculate new parameters with accommodation $M lW4&a|       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness bE#,=OI$   . Z.)t       Rant = 12.0 - 0.4*A                     'Radius of anterior lens uK$9Ll{lk       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ,)Ju[   1#*a:F&re       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 1[qLA! +       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens [los dnH^?   K/b_22]CC       tlens = 3.767 + 0.04*A                  'Lens thickness 1+qw$T   y?m/*hh`       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction d + /&?3   wF,UE_       'Adjust parameters to account for accommodation L[H5NUG!   h[1MtmNw       '************************************************************************* ujaGNg?,       'Aqueous thickness (Position of Lens) Co9QW/'i       '************************************************************************* R)z4n       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) RHq/JD-       GetCustomElement eID, entity 2FF4W54I   RwPN gRF       parID = FindFullName( "Geometry.Arizona Eye" ) P8>d6;o($   YN2sdG       ' Delete any shift(s) in z X*39c b(b       count = 0 g[Ib,la_a       While GetOperationCount(eID)>count RGg(%.           GetOperation eID, count, op NufLzg{           If op.Type="ShiftZ" Then 8X`tU<A b               DeleteOperation eID,count LbG_z =A               count=count-1 3k#/{Z           End If Bck7\           count=count+1 #u"k~La       Wend m&\h4$[kql   f3{MvAy[       'Set new shift in 9C[ywp       op.Type = "ShiftZ" gu<'QV"       op.val1 = taq PBxCx3a{       op.parent = parID ;A'Z4=*~       AddOperation eID, op \2}bi:e6       Print "Set aqueous humor thickness = " & taq-0.55 .J.-Mm`.   079'(%       '************************************************************************* gk+h8 LZ       'Radius and conic constant of anterior lens C;`XlQG `       '************************************************************************* w{uuSe       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) a,+@|TJ,i       GetConic eID, entity, curv, conic A~+S1   2fS[J'-o       SetConic eID, entity, 1/Rant, CCant 4Hn`'+b       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 2KN6}   %]6~Eq%s       '************************************************************************* {h2TD P       'Radius and conic constant of posterior lens r8&^>4       '************************************************************************* <Ib[82PU       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) &jczO-R^       GetConic eID, entity, curv, conic * Y7jl#7   9D}/\jM       SetConic eID, entity, 1/Rpost, CCpost t|!j2<e       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost OY5OJ*   }kK[S|XVO       '************************************************************************* 7&"n`@(.!       'Lens thickness (Position of posterior lens surface) Da:unVbU       '************************************************************************* HXYRH   ^Q ps>A(       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,4,V4 N   +1!qs,       ' Delete any z-shift(s) J}@z_^|"mJ       count = 0 |'+eMl       While GetOperationCount(eID)>count /`;n@0k>2           GetOperation eID, count, op D?,#aB"           If op.Type="ShiftZ" Then pM&Y Xb?               DeleteOperation eID,count hf<^/@^tK               count=count-1 |vMpXiMxxT           End If !!V#v9{           count=count+1 *"98L+       Wend hj$e|arB   f\1A!Yp       'Set new z-shift [NIlbjYH       op.Type = "ShiftZ" f%)zg(YlO       op.val1 = tlens %#Z/2<_       op.parent = parID zrv#Xa!O\       AddOperation eID, op  ^eGNgE       Print "Set lens thickness = " & tlens [kzd(u   X_G| hx       '************************************************************************* \U?n+6 7g       'Lens index of refraction 8W+gl=C~       '************************************************************************* <zy,5IlD       eID = FindMaterial( "Lens" ) GF:`>u{C       GetModelMaterial eID, mat GK}'R=    9F- )r'       mat.Nd = nlens P;8>5;U4-       SetModelMaterial eID, mat s(LT       Print "Set lens index of refraction = " & nlens KkMay   =!UR=Hq       '************************************************************************* ).HDru-2       'Pupil diameter J.+BD\pa       '************************************************************************* c$,_>tcP       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) <U9/InN0[   J3b4cxm       'Adjust pupil diameter (trimming volume inner hole) 9 ASb>A2~   ph|ZG6:        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" $BDBN_p   4YMX|1wd)       ' Adjust pupil location to just in front of the lens b*mKei       parID = FindFullName( "Geometry.Arizona Eye" ) vhT_=:x       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) HygY>s+3[       count = 0 FNQX7O52       While GetOperationCount(eID)>count .LRxP#B           GetOperation eID, count, op !lmWb-v%36           If op.Type="ShiftZ" Then s;YKeE!8               DeleteOperation eID,count rf9_eP               count=count-1 @C-dG7U.P           End If nCvPB/-           count=count+1 ZRUhAp'<qj       Wend /<3<. ~       op.Type = "ShiftZ" v !Kw< fp|       op.val1 = taq-0.01 Lj%{y.Rj       op.parent = parID Y?r po       AddOperation eID, op FM5e+$>@   Zz |MIGHm       Print "Set pupil diameter = " & pupilDiam &MgeYpd   xaKst p       'Update AZ Eye subassembly Description 6`"M       eID = FindFullName( "Geometry.Arizona Eye" ) QI[}(O7#6       GetEntity eID, entity l??;3kh1       entity.Description = "Accommodation = " & A & "D" ,rwuy [Q8       SetEntity eID, entity tue/4Q#7   Ei@M$Fd       Update 3Gr&p6       Print "DONE!" "x&C5l}n        ;;gK@?hJ   End Sub i(wgB\9i4   y9;#1:ic   如果屈光度是4，光瞳直径是4，则会输出如下数据： VzRx%j/i   dj[apuiF   Accommodation = 4 Diopters 9<]a!:!^   Pupil Diameter = 4 mm lZt( &^T   Set aqueous humor thickness = 2.81 <3O T>E [   Set anterior lens radius = 10.4 and conic constant = -2.375869 P8gXCX!>U   Set posterior lens radius = -4.424557 and conic constant = -3.081019 TQ1WVq }*   Set lens thickness = 3.927 #G,XDW2"w   Set lens index of refraction = 1.42672 mf|pNiQ,   Set pupil diameter = 4 g"!\\:M   DONE!

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