Arizona眼睛模型

kMQ /9~   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。 >Wr%usNxc   5M l=<^   模型 '{d@Gc6.   {]^Ixm-,f   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]u'7nO{{   Table 1. AZ眼睛模型的定义 y'_8b=*   OjUPvR2 0   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. @oAz   /d3Jd.l!   光源 ~29p|X<   >7>I1   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。 hN-@_XSw<I   hk~/W}sI   图1. 光源和提示信息使用 y"q a a   /\8Il+0   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。 "313eeIt%i   FO2e7p^Q   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。 Z4] n<~o   图2. 字母F光源的设定方法光 H-kX-7C   \Rny*px   图3. 字母F在视网膜上位置点列图 ~Bzzu %S   n"(!v7YNp   视网膜的散射 [*',pG   Wgwd?@uK   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。 Cu[-<>my   kU<t~+   图4. 视网膜朗伯散射设定 W$c@C02<   x}] 56f   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 ;m(iKwDt   u7!9H<{>P   图5. 视网膜重点采样规格设定 ^po@U"   OR<+y~Rv   脚本 4yl{:!la   ffrIi',@   内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： XIW0Z C    图6. 用户对话框的创建与编辑 .hl_zc#   图7. 用户对话框编辑器 ~G!JqdKJ0   |YJ83nSO~   如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 _;1{feR_   余下的脚本计算与屈光度有关的所有参数。 ,;)ZF   7>E.0DP   分析 AcH-TIgM/   *T5;dh (   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 cl4E6\?z   图7. 字母F在视网膜上颜色分析 L|=5jn9 :   f`9Mcli!   脚本代码 wcGK*sWG-   jj5S+ >4   Option Explicit     'Remove this to enable non-dimensioned variables to be used. G7%bY   ++0)KSvw   Dim entity As T_ENTITY F-yY(b]$   Dim op As T_OPERATION /A=w`[<   Dim mat As T_MODELMATERIAL r"7n2   Dim A As Double #.Rn6|V/4   Dim pupilDiam As Double Luq4q95]   Dim eID As Long pCIzpEsRs   Dim parID As Long isQ(O   Dim count As Integer @A/k"Ax{r   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Jz@~$L   Dim tlens As Double, nlens As Double xA] L0h]   Dim curv As Double, conic As Double [0H0%z#tU&   Dim ok As Long = 6%oW2E\   '%NglC[J   Sub Main 2QfN.<[-   oaoTd$/5       '用户输入对话框 =CX1jrLZ       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 tdy2ZPVtTV           TextBox 220,21,40,21,.TextBox1 'default: 0 zsFzg.$3&           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 0I&k_7_           OKButton 40,91,90,21 {MUB4-@?F$           CancelButton 190,91,90,21 T{YZ`[           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 * QgKo$IF           TextBox 220,49,40,21,.TextBox2 'default: 4 3*b5V<}'|       End Dialog bF'rK'',       Dim dlg As UserDialog cnv>&6a)   w0pMH p'Y       ok = Dialog (dlg) YGp+[|'   )9QtnM       If ok=0 Then    'cancel button was pressed Rj8%% G-pt           Print "Execution cancelled." JfY*#( {y           End X#Bb?Pv       End If MmuT~d/   wQkM:=t5       'Assign accommodation and pupil diameter & use defaults if field left empty @-N` W9       If dlg.TextBox1 = "" Then Cs'LrUB?=U           A = 0           'Default accommodation .KsR48g8       Else (\V i_           A = CDbl(dlg.TextBox1) % RSZ.       End If .L'w/"O   8[^'PIz       If dlg.TextBox2 = "" Then i!wU8@           pupilDiam = 4   'Default pupil diameter Q?{%c[s       Else FL0uY0K           pupilDiam = CDbl(dlg.TextBox2) 7nZPh3%       End If q'2vE;z Kb   sV^: u^       Print " " /zn=AAYb       Print "Accommodation = " & A & " Diopters" 4w4B\Na>l       Print "Pupil Diameter = " & pupilDiam & " mm" *7BfK(9T   [}RoZB&I       ' Calculate new parameters with accommodation 1J@Iekat       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 2z.ot'   g L;Kie6Z       Rant = 12.0 - 0.4*A                     'Radius of anterior lens ZzT =m*tQ&       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens D:)Wr, 26   Bf_$BCyGW       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens eRauyL"Q+       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens >ZA= 9v   sE1cvAw9l       tlens = 3.767 + 0.04*A                  'Lens thickness 8%@|/   C*9X;+S0J       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 8~sP{V%   0}{xH       'Adjust parameters to account for accommodation '6 KvB   xo:kT)       '************************************************************************* x3@-E       'Aqueous thickness (Position of Lens) f)I5=Ijy(       '************************************************************************* 4#U}bN       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) s 6H'}[E<       GetCustomElement eID, entity BHXi g~d   !e$gp(4       parID = FindFullName( "Geometry.Arizona Eye" ) K*6"c.D   bOY;IB _       ' Delete any shift(s) in z \-<BUG]=       count = 0 GK?ual1       While GetOperationCount(eID)>count 'U@o!\=a           GetOperation eID, count, op h}bfZL           If op.Type="ShiftZ" Then KKeMi@N               DeleteOperation eID,count \P\Z<z7jy               count=count-1 "S#FI           End If Tc2.ciU           count=count+1 QFh1sb)]d)       Wend f60w%   lQA5HzC\       'Set new shift in I[Ra0Q>([k       op.Type = "ShiftZ" 5&Oc`5QD       op.val1 = taq \l+v,ELX=       op.parent = parID K}*ets1s}       AddOperation eID, op .nV2n@SR       Print "Set aqueous humor thickness = " & taq-0.55 V0ze7tSG[f   =TB_|`5;j       '************************************************************************* ]`^! ]Ql       'Radius and conic constant of anterior lens ~zp8%lEe       '************************************************************************* e3~MU6       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 0^;2       GetConic eID, entity, curv, conic OATdmHW   #h5:b`fDF       SetConic eID, entity, 1/Rant, CCant jnH\}IB       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant {>&~kM@   De$AJl       '************************************************************************* ~ELY$G.xl       'Radius and conic constant of posterior lens MDMd$]CW       '************************************************************************* '3.\+^3       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) X-pbSq~5       GetConic eID, entity, curv, conic %1z;l.c   P8 X07IK       SetConic eID, entity, 1/Rpost, CCpost dj gk7       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost  56.!L   r924!zdbR       '************************************************************************* =C\Tl-$\f       'Lens thickness (Position of posterior lens surface) $ {yct       '************************************************************************* fHt\KP   >7U/TVd&       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) }$6L]    g?j)p y       ' Delete any z-shift(s) mvn- QP~"       count = 0 bzN[*X|       While GetOperationCount(eID)>count 'Waazk[@O           GetOperation eID, count, op I16FVdUun4           If op.Type="ShiftZ" Then Xr*I`BJ               DeleteOperation eID,count LG}{ibB               count=count-1 <'Q6\R}:vC           End If Y2|i>5/|<           count=count+1 [lmF2       Wend {DO9%ej)   !V|{(>+<       'Set new z-shift ~(kEGEF       op.Type = "ShiftZ" Nc[@QC{       op.val1 = tlens SX4*804a_       op.parent = parID "ubp`7%67       AddOperation eID, op 7Sdo*z       Print "Set lens thickness = " & tlens A;AQw   CS^6$VL7e       '************************************************************************* *>fr'jj1$       'Lens index of refraction /VR~E'Cy%       '************************************************************************* An2>]\L       eID = FindMaterial( "Lens" ) ]jT}]9Q$       GetModelMaterial eID, mat VKa+[   3(YvqPp&       mat.Nd = nlens ?kjQ_K       SetModelMaterial eID, mat jIh1)*]054       Print "Set lens index of refraction = " & nlens ?sfq g gi   Mj0,Y#=76       '************************************************************************* tE*BZXBlm       'Pupil diameter OB>Hiy        '************************************************************************* S^O9}<2g       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) `}X3f#eO&   |)x7qy`       'Adjust pupil diameter (trimming volume inner hole) ^eW<-n@^   }#z1>y!#       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" dsTX?E<R   M7#!Y=       ' Adjust pupil location to just in front of the lens Vl.,e1)6       parID = FindFullName( "Geometry.Arizona Eye" ) G p%po@A&       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ^ h=QpH       count = 0 )O'LE&kQ|       While GetOperationCount(eID)>count hSehJjEoM           GetOperation eID, count, op +!lDAkW0           If op.Type="ShiftZ" Then k 9i W1               DeleteOperation eID,count WJ{Iv] }9               count=count-1 d$IROZK-D           End If Xhe& "rM           count=count+1 @SX%q&-       Wend b{0a/&&1O       op.Type = "ShiftZ" Q)75?mn       op.val1 = taq-0.01 \Vc[/Qp7Bb       op.parent = parID c5]Xqq,       AddOperation eID, op /x3*oO1   B{Q}^Mcxy       Print "Set pupil diameter = " & pupilDiam j6%W+;{/pj   gt{kjrTv&       'Update AZ Eye subassembly Description s`yzeo       eID = FindFullName( "Geometry.Arizona Eye" ) qu B[S)2}       GetEntity eID, entity J[lC$X[       entity.Description = "Accommodation = " & A & "D" $dfc@Fn^x       SetEntity eID, entity _8G w Mj   a4:GGzt       Update <4rnOQ:       Print "DONE!" |E+.y&0;        Q,?_;,I}   End Sub i{$-[*WHiV   V?XQjH1X   如果屈光度是4，光瞳直径是4，则会输出如下数据： TdFU,   ^0]0ss;##R   Accommodation = 4 Diopters #]h X."b2   Pupil Diameter = 4 mm %q5dV<X'c   Set aqueous humor thickness = 2.81 ]B>76?2W   Set anterior lens radius = 10.4 and conic constant = -2.375869 rLTBBvV   Set posterior lens radius = -4.424557 and conic constant = -3.081019 }c G)$E   Set lens thickness = 3.927 bEcs(Mc~   Set lens index of refraction = 1.42672 9'MGv*Ho   Set pupil diameter = 4 2u.0AG    DONE!

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