Arizona眼睛模型

$;%-<*C o   人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 p+ymtPF   w$H=GF?"   模型 vrsO]ctI   t_&FK A   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。 }%EQ   Table 1. AZ眼睛模型的定义 N}wi<P:*)   J<:qzwh   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. wO!k|7:Z   yzhr"5_   光源 " *xQN "F   `LL#Aia   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。 xW{_c[oA   z3b8   图1. 光源和提示信息使用 2.Ym   R|h9ilc   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。 3ug{1M3   $kJvPwRO   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 "A^9WhUpJ   图2. 字母F光源的设定方法光 @B$ Y`eK\   MJ>9[hs   图3. 字母F在视网膜上位置点列图 w}<BO> z   ,,oiL   视网膜的散射 m~ \BkE/[l   3|%Q{U   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。 E9{Gaa/{   i/*&;   图4. 视网膜朗伯散射设定 :L`   qg w:Q   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。 `9eE139V='   I ms?^`N   图5. 视网膜重点采样规格设定 3a9Oj'd1M   lyKV^7}   脚本 zt!mx{l '   E0}`+x   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： fk`y}#7M   图6. 用户对话框的创建与编辑 b&p*IyJR   图7. 用户对话框编辑器 R{kZKD=   ="3Hc=1?R   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。 ~f2H@#   余下的脚本计算与屈光度有关的所有参数。 V@<tIui$   5)o-$1s A   分析 lRnst-inlI   q~.\NKc   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\lnH5A   图7. 字母F在视网膜上颜色分析 |~k=:sSz {   g^"",!J/   脚本代码 bAt%^pc=y   x;lIw)Ti   Option Explicit     'Remove this to enable non-dimensioned variables to be used. uXW<8( %W   ?Jm/v%0O   Dim entity As T_ENTITY p+#J;.   Dim op As T_OPERATION ' 0U+M{   Dim mat As T_MODELMATERIAL {<ymL}   Dim A As Double Jg3}U j2By   Dim pupilDiam As Double nK1XJp   Dim eID As Long <WtX> \]l(   Dim parID As Long x$I~y D   Dim count As Integer ZT95g   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double H:4r6-{   Dim tlens As Double, nlens As Double j"HB[N    Dim curv As Double, conic As Double cysYjuI i   Dim ok As Long s#?Y^bgH   8(q4D K\5u   Sub Main 0@{K'm/   Q<P],}?:       '用户输入对话框 SQWwxFJ       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 "lx}.           TextBox 220,21,40,21,.TextBox1 'default: 0 S*?'y           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ,d<wEB?\`           OKButton 40,91,90,21 . [+ObF9=           CancelButton 190,91,90,21 /"tVOv#           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 0FsGqFt           TextBox 220,49,40,21,.TextBox2 'default: 4 CT3wd?)z`       End Dialog "T?%4^:g       Dim dlg As UserDialog (A\qZtnyl   fyYT#r       ok = Dialog (dlg) W@AZ <(RI:   k# ZO4       If ok=0 Then    'cancel button was pressed DY^q_+[V           Print "Execution cancelled." h&L+Qx           End "d/x`Dx       End If Yq4_ss'nB   M' "S:       'Assign accommodation and pupil diameter & use defaults if field left empty tx}{E<\>$       If dlg.TextBox1 = "" Then lLxKC7b           A = 0           'Default accommodation .Gh-T{\V'       Else $TtCVR           A = CDbl(dlg.TextBox1) fOm=#:O       End If EN` --^   -OZXl       If dlg.TextBox2 = "" Then rr'RX           pupilDiam = 4   'Default pupil diameter B-|:l7       Else mWsVOf>g           pupilDiam = CDbl(dlg.TextBox2) fI`6]?W       End If Yb]eWLv   #q9jFW8       Print " " }I}RqD:`       Print "Accommodation = " & A & " Diopters" 52q@&')D4M       Print "Pupil Diameter = " & pupilDiam & " mm" 2TmQaDu%b   {[61 LQ6V9       ' Calculate new parameters with accommodation P-ys$=       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness WM*[+8h   ?lnX."eAdB       Rant = 12.0 - 0.4*A                     'Radius of anterior lens VT?JTW       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens L0qo/6|C   \,!FL))yC       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 5Lo{\7%       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens .8uJ%'$)   +IK~a9t       tlens = 3.767 + 0.04*A                  'Lens thickness `XB(d@%   HtgVD~[]       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction *^ \xH,.   R}8!~Ma`|       'Adjust parameters to account for accommodation /P<RYA~   ea3AcT6       '************************************************************************* CSRcTxH       'Aqueous thickness (Position of Lens) u^s{r`/       '************************************************************************* xv]P-q0       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Z`o}xV       GetCustomElement eID, entity ,6~c0]/   o_t2 Z       parID = FindFullName( "Geometry.Arizona Eye" ) 7C9qkQ Jqn   fCJ:QK!       ' Delete any shift(s) in z 2.p7fu       count = 0 Xnt`7L<L       While GetOperationCount(eID)>count ]QJLES           GetOperation eID, count, op /~{8/u3           If op.Type="ShiftZ" Then b&"=W9(V               DeleteOperation eID,count ZtlF]k:MV               count=count-1 lfOF]Kiqr           End If 1?]Gl+}           count=count+1 kn 5q1^       Wend ((7~o?Vbg   xop9*Z$       'Set new shift in QzT)PtX       op.Type = "ShiftZ" WpP8J1KN[       op.val1 = taq 57 Y(_h:       op.parent = parID Se9I1~mX       AddOperation eID, op y-cRqIM       Print "Set aqueous humor thickness = " & taq-0.55 _*0!6?c   <:-|>R".       '************************************************************************* ]7^OTrZ N       'Radius and conic constant of anterior lens M}!7/8HUC       '************************************************************************* $2A%y14       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) _&FcHwRy       GetConic eID, entity, curv, conic (~?P7RnU%   rV<yM$IA       SetConic eID, entity, 1/Rant, CCant G5|xWeNgA       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 1y$Bz?4   /0 s1q       '************************************************************************* ^Jcs0c @\       'Radius and conic constant of posterior lens 9w[7X"#n       '************************************************************************* AFGWlC#`       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) BB-E" <       GetConic eID, entity, curv, conic V.Dqbv   ,)hUL/r6       SetConic eID, entity, 1/Rpost, CCpost X3tpW`alo       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost [?r`8K2!,   =>-:o:Cu{       '************************************************************************* :/c=."z.       'Lens thickness (Position of posterior lens surface) {-2I^Ym 5i       '************************************************************************* (/14)"Sk   '*MNRduE6       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) k {_X%H/   @\e2Q&O       ' Delete any z-shift(s) /Z';#G,z       count = 0 i64a]=       While GetOperationCount(eID)>count rbS67--]           GetOperation eID, count, op P6&@fwJ<           If op.Type="ShiftZ" Then wo5"f}vd#               DeleteOperation eID,count U=\ZeYK.               count=count-1 y-m<&{q           End If F<Js"z+           count=count+1 x* *]@v"g       Wend @Iia>G@Rz   Z@>hN%{d+g       'Set new z-shift V%g$LrLVe       op.Type = "ShiftZ" C=2       op.val1 = tlens $YSAD\a<       op.parent = parID 6T! *YrS       AddOperation eID, op fNPHc_?Ybj       Print "Set lens thickness = " & tlens coT|t T   *kY\,r&!P       '************************************************************************* v!27q*;8H       'Lens index of refraction j$'L-kK+       '************************************************************************* -D?T0>       eID = FindMaterial( "Lens" ) Gu}|CFL\       GetModelMaterial eID, mat oXRmnt   +ObP[F       mat.Nd = nlens E;.<'t>       SetModelMaterial eID, mat ? acm5dN       Print "Set lens index of refraction = " & nlens HhDiGzOSi   }-?_c#G3       '************************************************************************* e` Z;}& ,       'Pupil diameter c?A(C#~ z       '************************************************************************* _p<W       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) j|gQe .,1   hNgbHzW       'Adjust pupil diameter (trimming volume inner hole) )8VrGg?   !G=!^RA       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ukHSHsR   F$QN>wPpM       ' Adjust pupil location to just in front of the lens =># S7=       parID = FindFullName( "Geometry.Arizona Eye" ) _+[;NBz       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 0O<g)%Vz>       count = 0 va F^[/ (g       While GetOperationCount(eID)>count u>o<ua p           GetOperation eID, count, op 0h/gqlTK1           If op.Type="ShiftZ" Then teH.e!S               DeleteOperation eID,count @[h)M3DFd               count=count-1 'Vq <;.A           End If \ofWD{*j           count=count+1 /?uA{/8       Wend iU"jV*P]       op.Type = "ShiftZ" >Eg/ir0       op.val1 = taq-0.01 *@/1]W       op.parent = parID H&\[iZ|-N       AddOperation eID, op #=C!Xx&   Q%)da)0:c       Print "Set pupil diameter = " & pupilDiam l/0"'o_0v#   q}P< Ejq}       'Update AZ Eye subassembly Description lx_jy>$}r       eID = FindFullName( "Geometry.Arizona Eye" ) _^K)>       GetEntity eID, entity )d5Hv2/0       entity.Description = "Accommodation = " & A & "D" JAJo^}}{b       SetEntity eID, entity C^9G \s'   >a/]8A       Update q-gp;Fm       Print "DONE!" dz@L}b*        HwfBbWHr'   End Sub x}v]JEIf[Q   :cU6W2EV   如果屈光度是4，光瞳直径是4，则会输出如下数据： {=mf/3.r   ?.Mw   Accommodation = 4 Diopters qd$Y"~Mco   Pupil Diameter = 4 mm \GhL{Awv&a   Set aqueous humor thickness = 2.81 JLgk?   Set anterior lens radius = 10.4 and conic constant = -2.375869 Bh3N6j+$d   Set posterior lens radius = -4.424557 and conic constant = -3.081019 6[ }~m\cY   Set lens thickness = 3.927 I~Y1DP)R   Set lens index of refraction = 1.42672 Wmri%   Set pupil diameter = 4 4@ EY+p   DONE!

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