Arizona眼睛模型

8lb%eb]U   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。 *x])Y~oQ   ,M6Sy]Aj   模型 C>$E%=h+_   ll6wpV0m   模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 TUDr\' @/f   Table 1. AZ眼睛模型的定义 ~j5x+yC   gb> }v7   在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 2f:Eof(B   ]*FVz$>XM   光源 4EZ9hA9+   aj}sc/Qa   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。 Q7$.LEioN   0-|byAh   图1. 光源和提示信息使用 O.Iu6D   Z@&Dki   除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 xw T%),   !Mim@!5M   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 2eC(Ijq[a   图2. 字母F光源的设定方法光 g'=B%eO$j:   y^Kph# F"   图3. 字母F在视网膜上位置点列图 ;._7jFj.   IS[thbzkZ   视网膜的散射 7.@TK&   0iK;Egwm   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。 =gvBz| +   P=&o%K,:f   图4. 视网膜朗伯散射设定 Q7C;1aO   _~tEw.fM5   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。 C,NxE5?h   &q~: ~   图5. 视网膜重点采样规格设定 uN^=<B?B   Q~Hh \Lt   脚本 CQr<N w   4jBC9b}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： P=+nB*hG   图6. 用户对话框的创建与编辑 UybW26C;aU   图7. 用户对话框编辑器 nF4a-H&Fo   /K{9OT@>   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。 V$icWu   余下的脚本计算与屈光度有关的所有参数。 xIGfM>uq   E+tB&   分析 ;w-qHha   Kryo}   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 xD /9F18   图7. 字母F在视网膜上颜色分析 jhX[fT1m   ;Y mTw   脚本代码 R:AA,^Z   @]c(V%x   Option Explicit     'Remove this to enable non-dimensioned variables to be used.  "t$k   -}4NT{E   Dim entity As T_ENTITY c$`4*6   Dim op As T_OPERATION iQ6epg1wB   Dim mat As T_MODELMATERIAL G,<T/f .{$   Dim A As Double za9)Q=6FD   Dim pupilDiam As Double $DC*i-}qFg   Dim eID As Long kR@Yl Yo   Dim parID As Long 6^n0[7   Dim count As Integer kctzNGF|   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 8W+gl=C~   Dim tlens As Double, nlens As Double l|+BC   Dim curv As Double, conic As Double 5P+t^\   Dim ok As Long p!V>XY'N^   j0GMT ri3   Sub Main 1w0OKaF5   f0SAP0M3       '用户输入对话框 _l], "[d       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 u=NSsTP&           TextBox 220,21,40,21,.TextBox1 'default: 0 /.eeOk           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 *tX{MSYW           OKButton 40,91,90,21 =GBI0&U           CancelButton 190,91,90,21 `L5~mb;7*           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 f8<o8*`7           TextBox 220,49,40,21,.TextBox2 'default: 4 @[?!s%*2       End Dialog &Q=ZwC7#       Dim dlg As UserDialog SL&hJs4c'   W Qzj[       ok = Dialog (dlg) q*AQq=   CG&`16KN7       If ok=0 Then    'cancel button was pressed DtWwGC           Print "Execution cancelled." 's!-80sd           End ,kp\(X[J       End If N_Af3R1_   :9Y$'+ <&H       'Assign accommodation and pupil diameter & use defaults if field left empty Ekm7 )d$       If dlg.TextBox1 = "" Then ixh47M           A = 0           'Default accommodation daAyx-       Else (5Tvsw`           A = CDbl(dlg.TextBox1) `}no9$l~       End If f Ka\7{R   5[9bWB{       If dlg.TextBox2 = "" Then ]AS"z<           pupilDiam = 4   'Default pupil diameter ~ZlC '       Else zMK](o1Vj           pupilDiam = CDbl(dlg.TextBox2) W:VP1 :       End If |"$uRV=qm   Zx?b<"k       Print " " M}"r#Plq       Print "Accommodation = " & A & " Diopters" 1GE|Wd        Print "Pupil Diameter = " & pupilDiam & " mm" `wTlyS3[   N(3R|Ii       ' Calculate new parameters with accommodation td-3h,\\       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness agOk*wH5   "x&C5l}n       Rant = 12.0 - 0.4*A                     'Radius of anterior lens pY^9l3y^       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens N<_Ko+VF   snp v z1iS       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Q\J,}1<`6       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Y&r]lD   E)t       tlens = 3.767 + 0.04*A                  'Lens thickness m^\TUj   {-63/z       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction PI?j_8   K,}w]b       'Adjust parameters to account for accommodation 9;r? nZT /   )Z@-DA*Q-       '************************************************************************* f R g=!<#%       'Aqueous thickness (Position of Lens) gS"Q=ZK"       '************************************************************************* q MS}t3X       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 2+92Q_+       GetCustomElement eID, entity +ydm,aKk   fjDpwb:x)       parID = FindFullName( "Geometry.Arizona Eye" ) q GPb   T"E(  F       ' Delete any shift(s) in z \w)?SVp       count = 0 $)e:8jS=       While GetOperationCount(eID)>count L,-u.vV           GetOperation eID, count, op d\XRUO[           If op.Type="ShiftZ" Then BSp$F WvT?               DeleteOperation eID,count ^^$vR[7               count=count-1 8gmn6dCf           End If RyRqH:p)3           count=count+1 Zy wK/D       Wend >4![&&   jgvh[@uB?       'Set new shift in {=At#*=A       op.Type = "ShiftZ" .:;fAJPf       op.val1 = taq gf$HuCh|       op.parent = parID u5gZxO1J5       AddOperation eID, op !J.rM5K       Print "Set aqueous humor thickness = " & taq-0.55 sdF3cX   cq^sq1A:       '************************************************************************* %9c|%#3       'Radius and conic constant of anterior lens 9|K*G~J       '************************************************************************* &?$\Y,{       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) y-`I) w%       GetConic eID, entity, curv, conic dV$!JTsd   g+Ph6W       SetConic eID, entity, 1/Rant, CCant mMxHR$2       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant FH n,]Tfx   p\txlT       '************************************************************************* 8)Tj H'       'Radius and conic constant of posterior lens tvWH04T       '************************************************************************* \FI^ Vk       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 712=rUI%!       GetConic eID, entity, curv, conic E0bFx5e5fu   &y3B)#dIJ       SetConic eID, entity, 1/Rpost, CCpost E2yz=7sv5       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 6IF|3@yD   ._BB+G       '************************************************************************* @c"yAy^t       'Lens thickness (Position of posterior lens surface) gO{W#%       '************************************************************************* A[Cg/ +Z   Pt3[|4L       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~M[>m~8   $PfV<Yj'B       ' Delete any z-shift(s) ty;o&w$       count = 0 jg^^\n       While GetOperationCount(eID)>count !`h~`-]O           GetOperation eID, count, op I;iR(Hf)?q           If op.Type="ShiftZ" Then VEo^ :o)r               DeleteOperation eID,count Y_shy6"KH               count=count-1 g Np-f           End If wR1K8b".DC           count=count+1 sRil>6QR       Wend 4O Zy&,   ,yi2O]5e>!       'Set new z-shift 9t\ [N/       op.Type = "ShiftZ" #y`k$20"       op.val1 = tlens o;'4c       op.parent = parID \1khyF'       AddOperation eID, op ?',}?{"c       Print "Set lens thickness = " & tlens ^*zW"s    bn|DRy       '************************************************************************* Dpp@*xX>       'Lens index of refraction I9s$bRbT       '************************************************************************* RQJ9MGw       eID = FindMaterial( "Lens" ) ?ZM^%]/+       GetModelMaterial eID, mat Lj-{t% }   a:xgjUt&5       mat.Nd = nlens qSCTFJ0       SetModelMaterial eID, mat 6 cr^<]v!       Print "Set lens index of refraction = " & nlens VG#$fRrZ   n K0hTQ       '************************************************************************* iqlVlm>E       'Pupil diameter ma`w\8a       '************************************************************************* :'b%5/ ^q       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) FrgV@4'2G   Fj48quW1\P       'Adjust pupil diameter (trimming volume inner hole) _/8y1)I   #s/{u RYQ       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" <X9T-b"$h   D)RdOldr       ' Adjust pupil location to just in front of the lens  2w;G4       parID = FindFullName( "Geometry.Arizona Eye" ) k@lXXII ?       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) AzW%+ LUD       count = 0 {K6Kx36       While GetOperationCount(eID)>count \Z8Y(]6*           GetOperation eID, count, op +&zb^C`J           If op.Type="ShiftZ" Then nEuct4BcL}               DeleteOperation eID,count s:G[Em1               count=count-1 GZ}*r{           End If tgS+"ugl           count=count+1 Z@8MhJ       Wend kkG_ +Y       op.Type = "ShiftZ" 4E,hcu       op.val1 = taq-0.01 ]VmzKA|h+       op.parent = parID `=PB2'       AddOperation eID, op ?cA8P.?^A   o7hH9iY       Print "Set pupil diameter = " & pupilDiam p}cd}@cQ6   "o~N42DLB%       'Update AZ Eye subassembly Description z;``g"dSw       eID = FindFullName( "Geometry.Arizona Eye" ) H{&a)!Ms       GetEntity eID, entity D;K&       entity.Description = "Accommodation = " & A & "D" ye56-T       SetEntity eID, entity F?!};~$=Z   nDwq!LEx%5       Update DHSU?o#jY       Print "DONE!" -DbH6u3        )+VHt   End Sub B=r]_&u-u   AD0ptHUBa   如果屈光度是4，光瞳直径是4，则会输出如下数据： 0#2T0zk   e@6RC bj   Accommodation = 4 Diopters jcT{ugpq   Pupil Diameter = 4 mm >}xAg7\^   Set aqueous humor thickness = 2.81  d)pz   Set anterior lens radius = 10.4 and conic constant = -2.375869 :%+^}    Set posterior lens radius = -4.424557 and conic constant = -3.081019 ptnMCF   Set lens thickness = 3.927 m1M;'tT@   Set lens index of refraction = 1.42672 a)YJ4\Qg[   Set pupil diameter = 4 "P>$=X~Zi   DONE!

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