Arizona眼睛模型

^b^}6L'Z   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。 O8)N`#1>+   %hCd*[Z}j   模型 QZv}\C-c   (qdvvu#E   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。 a<CACWsN.T   Table 1. AZ眼睛模型的定义 _BHEK   P9jPdls   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. ki'CW4x   4rrR;V"}   光源 qA5 Ug   Zgt(zh_l   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。 Js/QL=,   {pk]p~   图1. 光源和提示信息使用 e"&QQ-q   3oBR   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。 |(3"_   5[Uv%A?H#_   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。 yoG*c%3V?   图2. 字母F光源的设定方法光 x4-_K%   qrufnu5cC   图3. 字母F在视网膜上位置点列图 y85R"d   JasA w7   视网膜的散射 4Be\5Byr   ?@CbaX~+K   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。 C1o^$Q|j   Fx )BMP   图4. 视网膜朗伯散射设定 M.\V/OX   %jn)=;\   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 #*X\pjZ   UX%J?;g   图5. 视网膜重点采样规格设定 P7\?WN$p   t^~Qv   脚本 M< /   A\<W 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： |dhKeg_   图6. 用户对话框的创建与编辑 .I.B,wH8   图7. 用户对话框编辑器 ]i\;#pj}   ZQ{-6VCjl   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。 gUY~ l= c   余下的脚本计算与屈光度有关的所有参数。 tmi)LRF H   v?_L_{x;W   分析 G_<4% HM   X}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。 7=gcdfW,;x   图7. 字母F在视网膜上颜色分析 !RSJb   @MO/LvD   脚本代码  zPN:)   \P7<q,OGS   Option Explicit     'Remove this to enable non-dimensioned variables to be used. 3,-[lG@o   es<8"CcP   Dim entity As T_ENTITY y/+IPR   Dim op As T_OPERATION bvS6xU- J   Dim mat As T_MODELMATERIAL 6ZfL-E{   Dim A As Double HI7w@V 8Ed   Dim pupilDiam As Double LVT:oIQ   Dim eID As Long V!/9GeIF   Dim parID As Long %77 uc9}   Dim count As Integer aK/fZ$Qc   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double o59b#9   Dim tlens As Double, nlens As Double yK-DzAv   Dim curv As Double, conic As Double inh J|pe"   Dim ok As Long +lxjuEiae   OY8P   Sub Main U7Oa 13Qz    ?tA%A       '用户输入对话框 V-eRGSx       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 y%?'<j           TextBox 220,21,40,21,.TextBox1 'default: 0 .><-XJ           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ~d\^ynQ           OKButton 40,91,90,21 Lv#0-+]$Bt           CancelButton 190,91,90,21 kc(m.k!|f\           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 &gKDw!al           TextBox 220,49,40,21,.TextBox2 'default: 4 xkv%4H>       End Dialog )FNn       Dim dlg As UserDialog `QtkC>[   %uCsCl       ok = Dialog (dlg) ^`k;~4'd   U.X`z3q       If ok=0 Then    'cancel button was pressed ~6IY4']m*           Print "Execution cancelled." u / ]P           End S`$%C=a.       End If |1zfXG,R   Tdm|=xI       'Assign accommodation and pupil diameter & use defaults if field left empty hz*T"HJ]t       If dlg.TextBox1 = "" Then KIp^| k7>           A = 0           'Default accommodation Qj|rNeM_       Else T<"Bb[kH           A = CDbl(dlg.TextBox1) (T%?@'\       End If < Sgc6>)   (Ldvx_       If dlg.TextBox2 = "" Then OF03]2j7<|           pupilDiam = 4   'Default pupil diameter 9!FU,4 X       Else *CPpU|           pupilDiam = CDbl(dlg.TextBox2) n_Qua|R       End If FSm.o?>   3n)$\aBE       Print " " P;o{t       Print "Accommodation = " & A & " Diopters" :)i,K>y3i       Print "Pupil Diameter = " & pupilDiam & " mm" l i)6^f#   7B=VH r       ' Calculate new parameters with accommodation AwjXY,2       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness FzcXSKHV%   I;-Y2*       Rant = 12.0 - 0.4*A                     'Radius of anterior lens Wy}^5]R0E       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens kDDC@A $   ~^jPE)       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Qrt\bz h/}       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ~T sRUT   {kw%7}!       tlens = 3.767 + 0.04*A                  'Lens thickness :"MHmm=uU8   QS!Z*vG       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction !#:5^":;   :L@n(buRN       'Adjust parameters to account for accommodation !Ve0:$   ]WYV       '************************************************************************* CgmAxcK       'Aqueous thickness (Position of Lens) f}"eN/T       '************************************************************************* G{]RC^Zo       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) i@.Tv.NZ       GetCustomElement eID, entity B}[f]8jrM   z=) m6\       parID = FindFullName( "Geometry.Arizona Eye" ) Ak,JPzT   YLi6GY       ' Delete any shift(s) in z sYBmL]Hr       count = 0 ,}&TZkN{-       While GetOperationCount(eID)>count ?tL' X           GetOperation eID, count, op f)j*P<V           If op.Type="ShiftZ" Then %~PcJhz               DeleteOperation eID,count | bRU=dg               count=count-1 cz1+ XpU           End If NS2vA>n8R           count=count+1 ,|s*g'u       Wend %jy$4qAf%   @;`'s       'Set new shift in {'tfU       op.Type = "ShiftZ" [U/h'A.j       op.val1 = taq \c4jGJ       op.parent = parID P*BRebL:       AddOperation eID, op 6ICW>#fI`       Print "Set aqueous humor thickness = " & taq-0.55 N-?5[T"   F 5RL+rU(h       '************************************************************************* 't}\U&L.{       'Radius and conic constant of anterior lens Y&j`HO8f       '************************************************************************* 4qp|g'uXT       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) $QwpoVp`~       GetConic eID, entity, curv, conic YB7n}r23   WM?-BIlT=       SetConic eID, entity, 1/Rant, CCant l;0([_>*j       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant MGsQF#6]   TDDMx |{       '************************************************************************* pT->qQ3;       'Radius and conic constant of posterior lens ;7qIm83       '************************************************************************* ];hqI O#nM       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) tngB;9c+w       GetConic eID, entity, curv, conic ~q}L13^k   QR#>Ws       SetConic eID, entity, 1/Rpost, CCpost XJ\R'?j       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 'Og@<~/Xy   %S;AM\o4       '************************************************************************* &Y?t       'Lens thickness (Position of posterior lens surface) W&Fm;m@M       '************************************************************************* p"p~Bx   (cOe*>L;       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) N'VTdf?   6whPW .       ' Delete any z-shift(s) }6%XiP|       count = 0 &|{1Ws       While GetOperationCount(eID)>count qisvGHo           GetOperation eID, count, op (l^7EpNs           If op.Type="ShiftZ" Then B4RrUA32               DeleteOperation eID,count mG\QF0h               count=count-1 /S]RP>cQ           End If cb /Q<i           count=count+1 S[3"?$3S       Wend q7Hf7^a   g,._3.D       'Set new z-shift !2KQi=Ng       op.Type = "ShiftZ" z qq       op.val1 = tlens ;zJb("n       op.parent = parID uVn"L:_       AddOperation eID, op EcB !bf       Print "Set lens thickness = " & tlens xKSQz   -p_5T*R       '************************************************************************* s;9Du|0f^       'Lens index of refraction ad: qOm       '************************************************************************* dR]-R/1|       eID = FindMaterial( "Lens" ) E)$>t}$       GetModelMaterial eID, mat mp 8GHV   [ @eA o>       mat.Nd = nlens g4h{dFb|_       SetModelMaterial eID, mat "TJu<O"2       Print "Set lens index of refraction = " & nlens V+"%B rM   v;<gCzqQh       '************************************************************************* B[@q.n       'Pupil diameter SUUNC06V       '************************************************************************* :Ph>\aG       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) R|C`   t<##0#xS.       'Adjust pupil diameter (trimming volume inner hole) 1p.c6[9-   rQimQ|+       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" cpjwc@UMe   ,~d0R4)       ' Adjust pupil location to just in front of the lens 4]U=Y>\Sr       parID = FindFullName( "Geometry.Arizona Eye" ) F<I*?${[       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) n>ui'}L       count = 0 GJ*IH9YR       While GetOperationCount(eID)>count #h[>RtP:           GetOperation eID, count, op VC88r e`           If op.Type="ShiftZ" Then o0R?vnA=               DeleteOperation eID,count ,-e}Xw9               count=count-1 OS,!`8cw           End If ,>-D xS           count=count+1 AabQ)23R2       Wend :'DyZy2Fd       op.Type = "ShiftZ" = J;I5:J       op.val1 = taq-0.01 L\2"1%8Wj       op.parent = parID ZW [&7[4       AddOperation eID, op =-si| 1Z   MQ!4"E5"j       Print "Set pupil diameter = " & pupilDiam ^L2d%d\5   1nAm\/&       'Update AZ Eye subassembly Description 'v]0;~\mp>       eID = FindFullName( "Geometry.Arizona Eye" ) {6ZSf[Y6B       GetEntity eID, entity 1VgGF^cYR       entity.Description = "Accommodation = " & A & "D" MIZdk'.U       SetEntity eID, entity |!PL"]?   {^dq7!       Update h=A       Print "DONE!" hU$o^ICH        0*XsAz1,9   End Sub ev$:7}h=   E5^\]`9P   如果屈光度是4，光瞳直径是4，则会输出如下数据： OvX&5Q5   MI`qzC*%   Accommodation = 4 Diopters h< r(:.%!}   Pupil Diameter = 4 mm `"=>lu2H   Set aqueous humor thickness = 2.81 m%[e_eS   Set anterior lens radius = 10.4 and conic constant = -2.375869 w.x&3aG   Set posterior lens radius = -4.424557 and conic constant = -3.081019 Q-oDmjU   Set lens thickness = 3.927 ircF3P>a?   Set lens index of refraction = 1.42672 r ]7: ?ir   Set pupil diameter = 4 O{l4 f:51   DONE!

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