Arizona眼睛模型

NTS tk{s,   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。 #m{K   rC V&&09   模型 o65:)z u   -e_IDE   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。 mE^mQ [Dk   Table 1. AZ眼睛模型的定义 %p6"Sg*   o6,$;-?F_   在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. fz#e4+oH   vU0j!XqE   光源 o_ka'|   Ve#VGlI   多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 +O>!x#)&"   L\_MZ*<0[   图1. 光源和提示信息使用 -fIX6   QNj hA'[T   除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 b3N>RPsHS   ig:,:KN   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 S^'?sfq   图2. 字母F光源的设定方法光 8gwJ%"-K   xtMN<4#E   图3. 字母F在视网膜上位置点列图 =$;i   #D~atgR   视网膜的散射 @ de_|*c   c'B6E1}sx   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。 |3`Sd;^;   Fw? ;Y%   图4. 视网膜朗伯散射设定 jH#Tt;   [u\E*8   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。 :%cL(',Q   Y^$^B,   图5. 视网膜重点采样规格设定 HEHTj,T   n*~=O'   脚本 m"*j J.MX   Hf!o6 o   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： yk OJhd3   图6. 用户对话框的创建与编辑 m`CcU`s   图7. 用户对话框编辑器 U/'"w v1y   d7s? c   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。 p.^glz>B   余下的脚本计算与屈光度有关的所有参数。 9SF2   AB<|iJC   分析 K0$8t%Z.   / 4{6`   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 A.tONPi   图7. 字母F在视网膜上颜色分析 S^0Po% d   by; %k/   脚本代码 O|j(CaF   ))f%3_H   Option Explicit     'Remove this to enable non-dimensioned variables to be used. ^]:w5\DG   %&m/e?@%I   Dim entity As T_ENTITY ZYD Ll8   Dim op As T_OPERATION nI4Kuz`dF   Dim mat As T_MODELMATERIAL 1FCqkwq[   Dim A As Double 1%~yb Q   Dim pupilDiam As Double HnU; N S3J   Dim eID As Long "]h4L   Dim parID As Long 0gdFXh$!e   Dim count As Integer l ",JN.w   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double MTJ ."e<B   Dim tlens As Double, nlens As Double 3\_ae2GW   Dim curv As Double, conic As Double [iVCorU   Dim ok As Long feM%-   T\7z87Q   Sub Main 6UK{ 0\0   _K"|}bM       '用户输入对话框 `kb]tf       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 2Zt :]be           TextBox 220,21,40,21,.TextBox1 'default: 0 qW*JB4`?a           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 xVk|6vA7           OKButton 40,91,90,21 $D{KXkrd           CancelButton 190,91,90,21 1OB,UU"S$           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 G"w ?{W@           TextBox 220,49,40,21,.TextBox2 'default: 4 +oa\'.~?       End Dialog (B|4wR\       Dim dlg As UserDialog JGQlx-qv   NAd|n+[d       ok = Dialog (dlg) ):"Z7~j=   ?+#|h;M8       If ok=0 Then    'cancel button was pressed qxS=8#-`(           Print "Execution cancelled." ct,B0(]           End 9))E\U       End If \a\-hm   iSDE6       'Assign accommodation and pupil diameter & use defaults if field left empty $="t7C9S       If dlg.TextBox1 = "" Then g}>Sc=e<           A = 0           'Default accommodation ]7<}EG       Else k#mQLv           A = CDbl(dlg.TextBox1) )I7~<$w       End If V1 y"   6*yt^[W       If dlg.TextBox2 = "" Then g<C_3ap/           pupilDiam = 4   'Default pupil diameter O?`=<W/R       Else A+3,y<j\           pupilDiam = CDbl(dlg.TextBox2) ZlaU+Y(_[       End If pxm{?eBz   UjCQ W:[       Print " " &5JTcMC^       Print "Accommodation = " & A & " Diopters" lmmB=F       Print "Pupil Diameter = " & pupilDiam & " mm" Gk~QgD/Pix   mocR_3=Q?       ' Calculate new parameters with accommodation Wp2b*B=-       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness zxN,ys   BET3tiHV       Rant = 12.0 - 0.4*A                     'Radius of anterior lens yCznRd}J       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens +; /]'   8MUY       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens fL^+Qb}       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens >K]s)VuWR   &f12Q&jY7       tlens = 3.767 + 0.04*A                  'Lens thickness B[XV Tok   &T7|f!y       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction <'s_3AC   tE&@U$0>o       'Adjust parameters to account for accommodation _i@{:v   T-"zK r!       '************************************************************************* ,'=Tf=wq       'Aqueous thickness (Position of Lens) ly,3,ok       '************************************************************************* : ?K}.Kb       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4sU*UePr       GetCustomElement eID, entity [!^Q_O   }^T7S2_Qy       parID = FindFullName( "Geometry.Arizona Eye" ) w8MQA!=l   Xx.4K>j+j       ' Delete any shift(s) in z W lDcKY       count = 0 8GRp1'\Hi       While GetOperationCount(eID)>count &yu3nA:7D           GetOperation eID, count, op $U3|.4           If op.Type="ShiftZ" Then 7Jm&z/               DeleteOperation eID,count IZr~h9               count=count-1 4J#F;#iA           End If QU`M5{#           count=count+1 cvoE4&m!       Wend c!,&]*h"k   !m7`E       'Set new shift in d4y?2p ?3       op.Type = "ShiftZ" x2-i1#j`;       op.val1 = taq @|e4.(9A       op.parent = parID X5s.F%Np!       AddOperation eID, op +ZuT\P&kR5       Print "Set aqueous humor thickness = " & taq-0.55 \0}!qG![AA   !v^{n+       '************************************************************************* +C e[OG.       'Radius and conic constant of anterior lens =bn (9Gm!J       '************************************************************************* *$U+       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) (#|CL/&       GetConic eID, entity, curv, conic [73 \jT   <K^{36h       SetConic eID, entity, 1/Rant, CCant uc0 1{t0,       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant cr}T ? $\K   :5Y yI.T       '************************************************************************* 7(ni_|$|       'Radius and conic constant of posterior lens E5^P*6c(       '************************************************************************* R`IFKmA EJ       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) hW^*b:v{       GetConic eID, entity, curv, conic Se0!-NUK0   2#<)-Cak       SetConic eID, entity, 1/Rpost, CCpost pQQN8Y~^Y       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost O9+Dd%_KS#   bc+~g>o       '************************************************************************* _*tU.x|DP       'Lens thickness (Position of posterior lens surface) /G{;?R       '************************************************************************* ^Y;}GeA ,   e(e_p#       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 7H$I9e   |4$.mb.       ' Delete any z-shift(s) M 2pe*z       count = 0 y4@zi"G       While GetOperationCount(eID)>count -qI8zs$:5           GetOperation eID, count, op ?L%BD7           If op.Type="ShiftZ" Then }9Th`                DeleteOperation eID,count _H,xnh#nZ               count=count-1 d8)ps,           End If )bd)noZi           count=count+1 3/aK#TjK       Wend @3^D[   QLs9W&PG       'Set new z-shift bv&#ay7       op.Type = "ShiftZ" 9\QeH'A       op.val1 = tlens Po)!vL"        op.parent = parID ~pZ<VH;h       AddOperation eID, op lQ8h-Tz       Print "Set lens thickness = " & tlens GiZv0>* x   #Nv^F       '************************************************************************* K@f@vyw]       'Lens index of refraction |w{}h6a       '************************************************************************* }Wk^7[Y       eID = FindMaterial( "Lens" ) 3R}O3#l j,       GetModelMaterial eID, mat Q.U wtH   P&>!B,f       mat.Nd = nlens bpr       SetModelMaterial eID, mat s~z~9#G(6       Print "Set lens index of refraction = " & nlens .jXD0~N8q   '%H\k5^       '************************************************************************* 'bd|Oww1u       'Pupil diameter Nv~H797B       '************************************************************************* u~C,x3yr       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) W0I)< S   >=6 j:       'Adjust pupil diameter (trimming volume inner hole) } SNZl`>   !y$:}W?_       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" nF)b4`Nd   Z!& u_       ' Adjust pupil location to just in front of the lens [ ,&O       parID = FindFullName( "Geometry.Arizona Eye" ) :Rroz]*       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) iwXMe(k       count = 0 ; u@& [       While GetOperationCount(eID)>count U.GRN)fL4           GetOperation eID, count, op ?mA%`*=q           If op.Type="ShiftZ" Then {f(RYj               DeleteOperation eID,count 7'g{:dzS*3               count=count-1 sGp]jqX2,m           End If QVR8b3T@           count=count+1 @2`$ XWD       Wend (a9>gLI0       op.Type = "ShiftZ" ng{"W|       op.val1 = taq-0.01 [0?W>A*h       op.parent = parID s=H|^v       AddOperation eID, op W^k|*Y|   [S_qi,       Print "Set pupil diameter = " & pupilDiam )ppIO"\   Q H57[Yg       'Update AZ Eye subassembly Description fEB&)mM       eID = FindFullName( "Geometry.Arizona Eye" ) ED;rp9(       GetEntity eID, entity _/5#A+ ?       entity.Description = "Accommodation = " & A & "D" 6bwzNY 7       SetEntity eID, entity ZnAXb S   )j+G4       Update N\t( rp       Print "DONE!" =L]GQ=d        _+6aD|7x   End Sub m#,AD,s   )>]@@Trx   如果屈光度是4，光瞳直径是4，则会输出如下数据： O>3f*Cc   rQsYt/   Accommodation = 4 Diopters #8/pYQ;   Pupil Diameter = 4 mm l<)k`lrMX4   Set aqueous humor thickness = 2.81 -(lCM/h   Set anterior lens radius = 10.4 and conic constant = -2.375869 EXEB A&*   Set posterior lens radius = -4.424557 and conic constant = -3.081019 EM7Z g 65   Set lens thickness = 3.927 ku5vaP(   Set lens index of refraction = 1.42672 c0v6*O)   Set pupil diameter = 4 Yv/T6z@   DONE!

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