Arizona眼睛模型

tU>7jo[-p   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。 N~?(<DyZR   sn'E}.uhXH   模型 vJX0c\e   w.+G+r=   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。 o,$K=#Iv   Table 1. AZ眼睛模型的定义 oTTE<Ct[   $j4/ohwTDY   在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. c68,,rJO]i   }1.'2.<Y   光源 [LV>z   "DX2Mu=   多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 iRV=I,   w5t|C>   图1. 光源和提示信息使用 `<hMrhfh   hdH3Jb_hl(   除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 pTH5-l_f]   g?u=n`k]\   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 JC/nHM   图2. 字母F光源的设定方法光 /HdjPxH   *-E'$   图3. 字母F在视网膜上位置点列图 EbJc%%c   xgvwH?<   视网膜的散射 "cvhx/\1#   "}S6a?]V   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。 &&zsUAkS   m<J:6^H@   图4. 视网膜朗伯散射设定 ghTue*A   %kP=VUXj   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。 {??bJRT   q-/t?m0   图5. 视网膜重点采样规格设定 h"f_T [   lx> ."rW   脚本 h:KEhj\d?   a/[)A _-   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： $KS!vS7   图6. 用户对话框的创建与编辑 fGWXUJ   图7. 用户对话框编辑器 _s}`ohKvD   q RRvZhf   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。 TK0W=&6#A   余下的脚本计算与屈光度有关的所有参数。 k[y^7,r   ;R$2+9   分析 s? 2ikJq   .X:,]of   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 3`Xzp   图7. 字母F在视网膜上颜色分析 v^Rw9*w{   |<MSV KW   脚本代码 7j 88^59   {+EnJ"   Option Explicit     'Remove this to enable non-dimensioned variables to be used. ?}(B8^   s(r4m/   Dim entity As T_ENTITY {HFx+< JG   Dim op As T_OPERATION 'LR|DS[Ne   Dim mat As T_MODELMATERIAL ,vAcri 97   Dim A As Double bRr3:"=sE   Dim pupilDiam As Double h05<1>?|   Dim eID As Long 1*.*\4xo   Dim parID As Long FuG;$';H75   Dim count As Integer RrdLh z2N   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 5kojh _\   Dim tlens As Double, nlens As Double #$}A$sm   Dim curv As Double, conic As Double 7}`FXB   Dim ok As Long 4[)tO-v:Y   JEF;Q   Sub Main R@U4Ae{+   KN>h*eze       '用户输入对话框 qqys`.       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 LjIkZ'HuF           TextBox 220,21,40,21,.TextBox1 'default: 0 bD-OEB           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 1-E utq           OKButton 40,91,90,21 M`E}1WNQ?]           CancelButton 190,91,90,21 '%YE#1*gH           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 PKQ.gPu6*@           TextBox 220,49,40,21,.TextBox2 'default: 4 <(H<*Xf9       End Dialog <~S]jtL.j:       Dim dlg As UserDialog hE<Sm*HU   E()%IC/R       ok = Dialog (dlg) }$ Kd-cj+   E'NS$,h       If ok=0 Then    'cancel button was pressed 7 D{%           Print "Execution cancelled." }Yc5U,A;           End e3?z^AUXm       End If Y?L>KiM$   !Uv>>MCr       'Assign accommodation and pupil diameter & use defaults if field left empty WdB\n/BWB       If dlg.TextBox1 = "" Then i1'G_bo4F7           A = 0           'Default accommodation %jHe_8=o       Else GRaU]Z]ck           A = CDbl(dlg.TextBox1) Vhr6bu]       End If uBxoMx Wm   V^rL       If dlg.TextBox2 = "" Then ;>S|?M4GZ           pupilDiam = 4   'Default pupil diameter 7|GSs=       Else *z.rOY= 8           pupilDiam = CDbl(dlg.TextBox2) \jmZt*c       End If 5:C>:pAV   FZIC|uz       Print " " yvnDS"0<       Print "Accommodation = " & A & " Diopters" xW2?\em       Print "Pupil Diameter = " & pupilDiam & " mm" R1eWPtWs   *2rc Y       ' Calculate new parameters with accommodation X(\L1N       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness E0yx @Vx   CGkx_E]       Rant = 12.0 - 0.4*A                     'Radius of anterior lens H6Bw3I[       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens u?H.Z   d={o|Mf       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 3s67)n       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Ob}XeN(L3   Rjv;[       tlens = 3.767 + 0.04*A                  'Lens thickness L./c#b!{   `xx3JQv[       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction @|bJMi   cbs ;       'Adjust parameters to account for accommodation >5?:iaq z   HFlExau       '************************************************************************* vU]n0)<KB       'Aqueous thickness (Position of Lens) gS@<sO$d>       '************************************************************************* 7#NHPn       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~*9Ue@       GetCustomElement eID, entity I)s_f5'   TdT`Vf       parID = FindFullName( "Geometry.Arizona Eye" ) l2}X\N&q   6:6A"A       ' Delete any shift(s) in z #S x       count = 0 .l5-i@=W       While GetOperationCount(eID)>count p>#q* eU5           GetOperation eID, count, op %u_dxpx           If op.Type="ShiftZ" Then xSNGf@1b               DeleteOperation eID,count K=nDC.               count=count-1 ]61HQ           End If SM2 N3"\           count=count+1 9+xO2n       Wend Yyr9Kj:   Q\T?t       'Set new shift in DvB{N`COd       op.Type = "ShiftZ"  {$i>\)       op.val1 = taq 5Pxx)F9]       op.parent = parID {K6Z.-.`       AddOperation eID, op wf &Jd:)4t       Print "Set aqueous humor thickness = " & taq-0.55 41s\^'^&   9 wbQ$>G9       '************************************************************************* KfYU.Q       'Radius and conic constant of anterior lens V*5v JF0j       '************************************************************************* 2|d^#8)ZC       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) `wQs$!a        GetConic eID, entity, curv, conic kS=nH9   sR[!6[AA       SetConic eID, entity, 1/Rant, CCant Dw ZRx@       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant `b]wyP   VZ=:`)       '************************************************************************* (Y8LyY       'Radius and conic constant of posterior lens VJT /9O)Z|       '************************************************************************* >]xW{71F@       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) lX)AbK]nb       GetConic eID, entity, curv, conic 3\ ,t_6}   P:N>#G~z       SetConic eID, entity, 1/Rpost, CCpost TI/RJF b       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost /3K)$Er   ;1{=t!z=       '************************************************************************* QKB+mjMH#x       'Lens thickness (Position of posterior lens surface) *hJWuMfY,       '************************************************************************* 80'@+AD   ~cfXEjE6       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) m-ibS:   }LKD9U5;8       ' Delete any z-shift(s) `O%nDry       count = 0 cL~WDW/       While GetOperationCount(eID)>count 6)ln,{           GetOperation eID, count, op 0B!(i.w           If op.Type="ShiftZ" Then &rD8ng+$               DeleteOperation eID,count YG8V\4 SQ               count=count-1 *PV"&cx           End If 9_iwikD           count=count+1 VjNr<~|d       Wend J -Lynvqm   cs*E9       'Set new z-shift 1'Q6l       op.Type = "ShiftZ" KYJP`va6k       op.val1 = tlens =_zo       op.parent = parID 2IR ARZ,3       AddOperation eID, op E;x-O)(&       Print "Set lens thickness = " & tlens G9LWnyQt   {FKr^)g       '************************************************************************* l~f3J$Ok J       'Lens index of refraction GD]epr%V       '************************************************************************* u_ l?d       eID = FindMaterial( "Lens" ) zIu/!aw       GetModelMaterial eID, mat LjE3|+pJ   'N+;{8C-{       mat.Nd = nlens xH{-UQ3R       SetModelMaterial eID, mat <I tS_/z       Print "Set lens index of refraction = " & nlens 5[jS(1a`c   *AW v       '************************************************************************* Qkx*T9W       'Pupil diameter ej&.tNvq       '************************************************************************* 3en67l       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) S`zu.8%5   Xb>SA|6[|       'Adjust pupil diameter (trimming volume inner hole) gN:F50   .R"VLE|       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" {}ADsh@7d'   aK;OzB)       ' Adjust pupil location to just in front of the lens ksOsJ~3)       parID = FindFullName( "Geometry.Arizona Eye" ) R2a99#J       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Xm>zT'B_tJ       count = 0 43B0ynagN       While GetOperationCount(eID)>count E z}1Xse           GetOperation eID, count, op JZ`h+fAt           If op.Type="ShiftZ" Then U'(zKqC               DeleteOperation eID,count %sOY:>               count=count-1 (?R!y -           End If w)zJ $l           count=count+1 ]bh%pn       Wend *nJ,|T       op.Type = "ShiftZ" df@NV Ld       op.val1 = taq-0.01 E~fb#6       op.parent = parID E]/2u3p       AddOperation eID, op 0>td[f   d wG!]j>:_       Print "Set pupil diameter = " & pupilDiam 76@W:L*J$J   e3TKQ(       'Update AZ Eye subassembly Description 5G\OINxy       eID = FindFullName( "Geometry.Arizona Eye" ) %\sE\]K       GetEntity eID, entity XK3O,XM       entity.Description = "Accommodation = " & A & "D" -i{_$G8W/c       SetEntity eID, entity =KOi#;1   pMHl<HH       Update ^U5N!"6R       Print "DONE!" v9*+@        a dr\l5pWQ   End Sub Oj_]`   /tj]^QspS   如果屈光度是4，光瞳直径是4，则会输出如下数据： T[1iZ   7AT8QC`u   Accommodation = 4 Diopters |rk.t g9   Pupil Diameter = 4 mm \UZGXk   Set aqueous humor thickness = 2.81 iw/~t   Set anterior lens radius = 10.4 and conic constant = -2.375869 >xS({1A}   Set posterior lens radius = -4.424557 and conic constant = -3.081019 u_' -vZ_   Set lens thickness = 3.927 iv+a5   Set lens index of refraction = 1.42672 Q%d%Io\-t   Set pupil diameter = 4 ;k`51=Wi   DONE!

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