Arizona眼睛模型

+(z[8BJl   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。 .u=|h3&   dWe %6s;    模型 &3xda1H   83p8:C.Ze   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。 N3a ]!4Y\   Table 1. AZ眼睛模型的定义 }_mMQg2>=   SQ]M"&\{y   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. ,2i1 4H   h?}S|>9   光源 rOj(THoc{   I3izLi   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。 %K7;ePu   Nez '1   图1. 光源和提示信息使用 _JA)""l%   ^gNbcWc7CU   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。 $fT#Wva-\d   cWo__EE   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 "Vp:Sq9y   图2. 字母F光源的设定方法光 ;XlCd[J<   qSD3]Dv"   图3. 字母F在视网膜上位置点列图 /F''4%S?E   hx/A215L   视网膜的散射 St> E\tXp   r>PKl'IbE   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ,JTyOBB<I   FL&Y/5   图4. 视网膜朗伯散射设定 !x||ObW\H   e 0Z2B2   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 ]"YXa~ b   x")Bmw$   图5. 视网膜重点采样规格设定 qg<Y^y   m5HMtoU   脚本 -Ekf T_   MBU4Awj   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： g2rH"3sC   图6. 用户对话框的创建与编辑 A@4{-e\   图7. 用户对话框编辑器 [D<(xr&N%   D5].^* AbZ   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。 H7<g5pv   余下的脚本计算与屈光度有关的所有参数。 ^EW6}oj[   f9IqcCSW   分析 A_2lG!! 6   +bb-uoZf   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 R?N+./{   图7. 字母F在视网膜上颜色分析 D`.\c#;cN   YfseX;VX   脚本代码 CWB<I   "+ k}#<P4\   Option Explicit     'Remove this to enable non-dimensioned variables to be used. m")p]B&i=   YG*}F|1   Dim entity As T_ENTITY 7qWa>fX   Dim op As T_OPERATION -7J~^m2x   Dim mat As T_MODELMATERIAL D$w?   Dim A As Double o"A?Aq   Dim pupilDiam As Double { Q!Xxe>6   Dim eID As Long &Wk:>9]Jrb   Dim parID As Long *7#5pT~   Dim count As Integer f3h]t0M   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double vNZ"x)?   Dim tlens As Double, nlens As Double 8| +@A1)&4   Dim curv As Double, conic As Double 1 .o0"   Dim ok As Long rTJ;s   /;u=#qu(E-   Sub Main q%)."10}]   M~Er6Zg       '用户输入对话框 i~5'bSqc       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 PfhKomt"           TextBox 220,21,40,21,.TextBox1 'default: 0 Y 7?q`           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 d4A:XNKB           OKButton 40,91,90,21 3u s^\w#           CancelButton 190,91,90,21 R[m+s=+           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 zcio\P=^|B           TextBox 220,49,40,21,.TextBox2 'default: 4 tdp>vI!       End Dialog V~Jt       Dim dlg As UserDialog t+ ,2 p|B   v`@N R06       ok = Dialog (dlg) GNW.n(a   GK3cQw       If ok=0 Then    'cancel button was pressed 64^3ve3/a=           Print "Execution cancelled." 5 (q4o`           End _5OxESE       End If Zl.,pcL   S]4!uv^y       'Assign accommodation and pupil diameter & use defaults if field left empty &7{yk$]*       If dlg.TextBox1 = "" Then `+0P0(bn           A = 0           'Default accommodation 6.|[;>Km       Else EQ"+G[j~x           A = CDbl(dlg.TextBox1) "K;""]#wg0       End If =t|,6Vp   \(zUI       If dlg.TextBox2 = "" Then PMQlJ&           pupilDiam = 4   'Default pupil diameter uOh        Else iWkC:fQz           pupilDiam = CDbl(dlg.TextBox2) 3wPUP+)c7       End If dkQP.Tj$i   {c<cSrfI       Print " " :1v.Jk       Print "Accommodation = " & A & " Diopters" ke2M &TV       Print "Pupil Diameter = " & pupilDiam & " mm" ZJ/K MW   `<hMrhfh       ' Calculate new parameters with accommodation hdH3Jb_hl(       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness pTH5-l_f]   g?u=n`k]\       Rant = 12.0 - 0.4*A                     'Radius of anterior lens JC/nHM       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens /HdjPxH   *-E'$       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 02YmV%       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens xgvwH?<   "cvhx/\1#       tlens = 3.767 + 0.04*A                  'Lens thickness z0&Y_Up+5   &&zsUAkS       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction j&q%@%Gm   \]3[Xw-$       'Adjust parameters to account for accommodation E+$D$a   ~CHVU3       '************************************************************************* F><ficT       'Aqueous thickness (Position of Lens) ezS@`_pR;       '************************************************************************* 9vCCE[9       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) w/9%C(w6       GetCustomElement eID, entity u7},+E)+B   S.?DR3XLc       parID = FindFullName( "Geometry.Arizona Eye" ) <driD'=F   B'bOK`p       ' Delete any shift(s) in z vz&88jt       count = 0 O<MO2U+^x       While GetOperationCount(eID)>count :4r*Jju<V           GetOperation eID, count, op ;R$2+9           If op.Type="ShiftZ" Then U& #`5u6'j               DeleteOperation eID,count ((=T E               count=count-1 wR"17z7[]           End If /-+hMYe           count=count+1 Q^X}7Z|T       Wend xl@~K^c]   b,>>E^wd!       'Set new shift in DHZ`y[&}|N       op.Type = "ShiftZ" ZVrZkd`       op.val1 = taq Ko|gH]B'       op.parent = parID D2RvFlAXu       AddOperation eID, op $weC '-n@       Print "Set aqueous humor thickness = " & taq-0.55 aj<r=   ^z51f>C       '************************************************************************* rE0%R+4?       'Radius and conic constant of anterior lens m|v$F,Lv       '************************************************************************* `O`MW} c       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) b.RFvq5Z       GetConic eID, entity, curv, conic yR"mRy1   bCiyz+VyJn       SetConic eID, entity, 1/Rant, CCant B&<P>AZ       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant DcE4r>8B   JEF;Q       '************************************************************************* R@U4Ae{+       'Radius and conic constant of posterior lens | /n       '************************************************************************* I R8yE`(h       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 45OAJ?N       GetConic eID, entity, curv, conic s'bTP(wl9   Zay%QNsb       SetConic eID, entity, 1/Rpost, CCpost wJ"]H!r0       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost c0;rvw7   "2p\/VfA       '************************************************************************* @Gy.p5J8       'Lens thickness (Position of posterior lens surface) amQTPNI       '************************************************************************* ^]Z@H/]H   U*,\UF       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) '8(UiB5d   X#zp,7j?       ' Delete any z-shift(s) S)/548=`       count = 0 WBb*2       While GetOperationCount(eID)>count Ty#sY'%           GetOperation eID, count, op hDQk z qW           If op.Type="ShiftZ" Then =^\?{oV               DeleteOperation eID,count "oyBF CW               count=count-1 12;YxW>[           End If Z]x6 np           count=count+1 1g jGaC       Wend ~O]{m,)n   e1%kW1Z9       'Set new z-shift kt=&mq/B       op.Type = "ShiftZ" 4YR{ *       op.val1 = tlens $\|Q+7lQ       op.parent = parID 4C;y2`C       AddOperation eID, op ZX#60o8       Print "Set lens thickness = " & tlens i%, 't   cBv"d ~       '************************************************************************* $?dQ^]<,       'Lens index of refraction z^s\&gix       '************************************************************************* EVC]B}       eID = FindMaterial( "Lens" ) Hsd76z#8       GetModelMaterial eID, mat >Bu9 D   29m$S7[       mat.Nd = nlens *u",-n       SetModelMaterial eID, mat *)Cr1d k       Print "Set lens index of refraction = " & nlens ZKq#PB/.   @|bJMi       '************************************************************************* adAdX;@e`       'Pupil diameter 7[UD;&\k       '*************************************************************************  sFnR;       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) @LSh=o+   f=u +G       'Adjust pupil diameter (trimming volume inner hole) O.-n&U9   ;NrPMz       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" )Y9\>Xj7   9*huO#       ' Adjust pupil location to just in front of the lens y)a)VvU":       parID = FindFullName( "Geometry.Arizona Eye" ) @65xn)CD{       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 08D:2 z1z       count = 0 6(uZn=       While GetOperationCount(eID)>count M ?AX:0           GetOperation eID, count, op ]f&f_"D           If op.Type="ShiftZ" Then 4>a(!ht               DeleteOperation eID,count ByO?qft>u               count=count-1 TbN{ex*           End If SynRi/BRmw           count=count+1 bN03}&I       Wend Bq1}"092       op.Type = "ShiftZ" <;O^3_'       op.val1 = taq-0.01 :Fu7T1       op.parent = parID [t$ r)vX       AddOperation eID, op +."cbqGP_q   8lGM>(:o       Print "Set pupil diameter = " & pupilDiam I%GQ3D"=   G--(Ef%v'       'Update AZ Eye subassembly Description ZS;V?]\(       eID = FindFullName( "Geometry.Arizona Eye" ) V*5v JF0j       GetEntity eID, entity 2|d^#8)ZC       entity.Description = "Accommodation = " & A & "D" `wQs$!a        SetEntity eID, entity R5%CK_   sR[!6[AA       Update a]xGzv5       Print "DONE!" u@`a~        wfpl]d!   End Sub 5]upfC6   ey,f igjd.   如果屈光度是4，光瞳直径是4，则会输出如下数据： Xt$P!~Lu   QB!_z4UJ_;   Accommodation = 4 Diopters .4tu{\YX   Pupil Diameter = 4 mm oP%5ymL%J   Set aqueous humor thickness = 2.81 _DT,iF*6   Set anterior lens radius = 10.4 and conic constant = -2.375869 bt _c$TN   Set posterior lens radius = -4.424557 and conic constant = -3.081019 eEP{?F^I[   Set lens thickness = 3.927 bgKC^Q/F   Set lens index of refraction = 1.42672 ir>h3Zk   Set pupil diameter = 4 N3aqNRwlk   DONE!

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