Arizona眼睛模型

3)<yod=   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。 ]g3JZF-   y&$A+peJ 1   模型 :1QI8%L'$i   @1roe G   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。 K<3A1'_   Table 1. AZ眼睛模型的定义 ( Y[Q,   @Md/Q~>   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. U)o-8OEZ9   ~g]Vw4pv   光源 JX;<F~{.   8b&/k8i:   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。  JYI,N   lfow1WRF   图1. 光源和提示信息使用 V+Y%v.F   g wRZ%.Cn   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。 vm8eZG|   WaRw05r   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。 Vx u0F]%   图2. 字母F光源的设定方法光 6Pl<'3&   (=AWOU+   图3. 字母F在视网膜上位置点列图 <dtGK~_   k(nW#*N_   视网膜的散射 z2~til   GR_-9}jQP   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。  +SU8 +w   b{&)6M)zo   图4. 视网膜朗伯散射设定 'o2Fa_|<#   P/eeC"   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。 zY{A'<\O   zR:L!S   图5. 视网膜重点采样规格设定 ITI)soa~   gPI ?C76   脚本 oJz^|dW   N:/D+L   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： +~$ ]}%   图6. 用户对话框的创建与编辑 aeJHMHFc   图7. 用户对话框编辑器 77f9(~ZnT   /$?}YL,   如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 aB&&YlR=n<   余下的脚本计算与屈光度有关的所有参数。 :g0zT[f   +I|vzz`ZVr   分析 |u<7?)mp   R&k<AZ   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 m<Dy<((_I   图7. 字母F在视网膜上颜色分析 .Yn_*L+4*   ?+@?Up0wGO   脚本代码 f.$af4 u   'zTLl8P   Option Explicit     'Remove this to enable non-dimensioned variables to be used. 0S!K{xyR   .W!i7   Dim entity As T_ENTITY zRr*7G   Dim op As T_OPERATION ]2KihP8z x   Dim mat As T_MODELMATERIAL _]H&,</   Dim A As Double S2&4g/   Dim pupilDiam As Double sUQ@7sTj   Dim eID As Long !_)[/q"   Dim parID As Long bROLOf4S   Dim count As Integer \_f(M|   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double T(Eugl"   Dim tlens As Double, nlens As Double )3EY;   Dim curv As Double, conic As Double w<(pl%   Dim ok As Long !Wnb|=j   vA8nvoi   Sub Main OQJ6e:BGt   j A%u 5V       '用户输入对话框 e(t\g^X       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 H**Xu;/5@           TextBox 220,21,40,21,.TextBox1 'default: 0 +cN8Y}V           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 1mG-}           OKButton 40,91,90,21 -uf|w?           CancelButton 190,91,90,21 eeB{c.#           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ZUd -<y           TextBox 220,49,40,21,.TextBox2 'default: 4 zK@@p+n_#.       End Dialog Rima;9.Y0       Dim dlg As UserDialog 1=V-V<   ~Mxvq9vaD       ok = Dialog (dlg) wbl&   wnC81$1l~       If ok=0 Then    'cancel button was pressed *$g-:ILRuZ           Print "Execution cancelled." }5"u[Z.           End C~/a-       End If v.qrz"98-   vEJbA       'Assign accommodation and pupil diameter & use defaults if field left empty 8$} <, c(       If dlg.TextBox1 = "" Then /%^#8<=|U           A = 0           'Default accommodation i9x+A/o[       Else .$vK&k           A = CDbl(dlg.TextBox1) ] t"Ss_,       End If gg2(5FPP   A*BeR0(       If dlg.TextBox2 = "" Then I; rGD^           pupilDiam = 4   'Default pupil diameter \'O"~W       Else nBYZ}L q           pupilDiam = CDbl(dlg.TextBox2) O:K2Y5R?B       End If }N52$L0[   .7X^YKR       Print " " X"%gQ.1|{j       Print "Accommodation = " & A & " Diopters" 4j^ @wV'       Print "Pupil Diameter = " & pupilDiam & " mm" Xsa].   JB<t6+"rD       ' Calculate new parameters with accommodation AA>P`C$&M       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness dk^~;m#iN   $[ *w"iQ       Rant = 12.0 - 0.4*A                     'Radius of anterior lens G 01ON0       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens P]C<U aW'!   pd$[8Rmj_       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ^S; -fYW2       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens xyXa .   }^\oCR@       tlens = 3.767 + 0.04*A                  'Lens thickness 2&cT~ZX&'   , W?VhO       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction j1<Yg,_.p   wC'Szni       'Adjust parameters to account for accommodation J<lW<:!3]   cU       '************************************************************************* RxQ*       'Aqueous thickness (Position of Lens) xoME9u0x4       '************************************************************************* n+R7D.<q!!       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) nO-#Q=H,       GetCustomElement eID, entity 1xvu<|F   eyxW 0}[       parID = FindFullName( "Geometry.Arizona Eye" ) |I=T@1_D   kq-) ^,{y       ' Delete any shift(s) in z t6t!t*jO       count = 0 DHRlWQox       While GetOperationCount(eID)>count noj0F::m`j           GetOperation eID, count, op nJ;.Td           If op.Type="ShiftZ" Then izR"+v               DeleteOperation eID,count }6ldjCT/,               count=count-1 FP>2C9:d           End If NHE18_v5           count=count+1 e'<)V_       Wend `d(ThP;g   ?V=CB,^       'Set new shift in 9- #R)4_       op.Type = "ShiftZ" Dt1jW       op.val1 = taq Gq P5Kx+=       op.parent = parID wuo,kM       AddOperation eID, op VxBo1\'       Print "Set aqueous humor thickness = " & taq-0.55 19] E 5'AI   }-2|XD%]       '************************************************************************* s#GLJl\E_P       'Radius and conic constant of anterior lens l+b~KU7~l       '************************************************************************* {4PwLCy       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) u%!@(eKM-       GetConic eID, entity, curv, conic ;FEqe49   2&5K.Ui%       SetConic eID, entity, 1/Rant, CCant [N'h%1]\       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant O".=r}   C_Wc5{       '************************************************************************* uw8f ~:LT       'Radius and conic constant of posterior lens p K$`$H       '************************************************************************* v` r:=K       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) p]"4#q\(       GetConic eID, entity, curv, conic #LNED)Vg   |[y6Ua0       SetConic eID, entity, 1/Rpost, CCpost y_[vr:s5pG       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost !Z6{9sKR=]   ss-D(K"       '************************************************************************* "Yy n/       'Lens thickness (Position of posterior lens surface) @j/&m]6%-D       '************************************************************************* LH6vLuf   K> e7pu       parID = FindFullName( "Geometry.Arizona Eye.Lens" )  T]$U""   tf G@&&%9       ' Delete any z-shift(s) 'B}qZCy W       count = 0 FgO)DQm       While GetOperationCount(eID)>count bPMhfK2 %           GetOperation eID, count, op hv+zGID7           If op.Type="ShiftZ" Then -K$)DvV^(E               DeleteOperation eID,count :hA#m[               count=count-1 =\d?'dII:           End If dqAw5[qMJ           count=count+1 1:wQ.T       Wend w*Ihk)   o"SMbj       'Set new z-shift NEF# }s2=       op.Type = "ShiftZ" <-0]i_4sK       op.val1 = tlens tg/H2p^Y       op.parent = parID A)KZa "EX       AddOperation eID, op |7Kbpj       Print "Set lens thickness = " & tlens B-ESFATc   xLn%hxm?,       '************************************************************************* 9>$p       'Lens index of refraction L rPkxmR       '************************************************************************* B1Oq!k       eID = FindMaterial( "Lens" ) <\FH fE       GetModelMaterial eID, mat |&jXp%4T   Aa]"       mat.Nd = nlens SY8C4vb'h       SetModelMaterial eID, mat 'm9` 12H       Print "Set lens index of refraction = " & nlens L8n|m!MOD   "h ^Z       '************************************************************************* A70d\i       'Pupil diameter Qci]i)s$js       '************************************************************************* b>$S<td       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ?hM64jI|   59-c<I/}f       'Adjust pupil diameter (trimming volume inner hole) J. @9zA&   RGX=)       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" }&3~|kP~O   yppo6HGD       ' Adjust pupil location to just in front of the lens k+4#!.HX^       parID = FindFullName( "Geometry.Arizona Eye" ) {_dvx*M       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ,Lt[\_       count = 0 [8*)8jP3       While GetOperationCount(eID)>count a}uSm/S           GetOperation eID, count, op l@:0e]8|o           If op.Type="ShiftZ" Then KG5>]_GH               DeleteOperation eID,count ]:\dPw `A               count=count-1 [1KuzCcK}           End If IIqUZJ           count=count+1 %PJQ%~ A       Wend 1i] ^{;]       op.Type = "ShiftZ" o? $.fhD        op.val1 = taq-0.01 llsfTrp       op.parent = parID snikn&       AddOperation eID, op c0fo7|   >"<Wjr8W!$       Print "Set pupil diameter = " & pupilDiam 4Z,!zFS$`   ]0\MmAJRn       'Update AZ Eye subassembly Description CWS4lx       eID = FindFullName( "Geometry.Arizona Eye" ) 4H<lm*!^       GetEntity eID, entity cFWc<55aX6       entity.Description = "Accommodation = " & A & "D" \^%}M!tan       SetEntity eID, entity !Rt>xD   4a]P7fx-       Update '`<w#z}AF       Print "DONE!" PiYxk+N        ofv)SCjd   End Sub = 9]~yt   J)C/u{o   如果屈光度是4，光瞳直径是4，则会输出如下数据： #C3.Jef   +?!(G}5   Accommodation = 4 Diopters ?I@ W:#>o   Pupil Diameter = 4 mm ""|Qtubv   Set aqueous humor thickness = 2.81 pV"R|{#V   Set anterior lens radius = 10.4 and conic constant = -2.375869 mdgi5v   Set posterior lens radius = -4.424557 and conic constant = -3.081019 ?S$P 9^ii'   Set lens thickness = 3.927 I 2|Bg,e   Set lens index of refraction = 1.42672 #N cK X   Set pupil diameter = 4 C73kJa   DONE!

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