Arizona眼睛模型

FL/y{;   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。 Rl3KE)<   ,3GM'e{hV   模型 q97Dn[>3   kf-ZE$S4   模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 Z1\_[GA   Table 1. AZ眼睛模型的定义 |E U}&k2   P). @o.xl   在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. *TE6p   FAE>N-brQ   光源 +-ieaF   P$]Vb'Fz   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。 Q1&: +7%   #wM0p:<   图1. 光源和提示信息使用 _7$j>xX   4ItXZo   除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 o{UwUMw5`   lrq !}\aX   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 zq4mT;rqz   图2. 字母F光源的设定方法光 M_79\Gz"   yg\A&0I   图3. 字母F在视网膜上位置点列图 e>z7?"N   %$]u6GKabi   视网膜的散射 gdCU1D \   7qW:^2y   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。 uVscF 4   M"p$9t   图4. 视网膜朗伯散射设定 z+-k4   k,?Y`s   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 &]vd7Q.t   e@8I%%V ,   图5. 视网膜重点采样规格设定 'a"<uk3DT   3\D jV2t   脚本 wau81rSd    9=< Z>   内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： 1Kc*MS   图6. 用户对话框的创建与编辑 I}k!i+Yl   图7. 用户对话框编辑器 ]E=JUYf0   /;.M$}Z>`   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。 ARU ,Wtj#   余下的脚本计算与屈光度有关的所有参数。 a-QHm;_S   z>y,}#D?C   分析 |qbJ]v!   j/Bzbjq"   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 ,Y!T!o}1   图7. 字母F在视网膜上颜色分析 UZ](X/   #Wc)wL-Tg   脚本代码 O]2h=M@q.   )Fm   Option Explicit     'Remove this to enable non-dimensioned variables to be used. '!f5|l9SC   `H+Eo<U   Dim entity As T_ENTITY 4G`YZZQ   Dim op As T_OPERATION >nr1|2   Dim mat As T_MODELMATERIAL o9eK7*D   Dim A As Double ]e"NJkcm   Dim pupilDiam As Double R2~Rqlti   Dim eID As Long d!wd,Xj}   Dim parID As Long gJF;yW4   Dim count As Integer #K)HuT   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double {H>iL   Dim tlens As Double, nlens As Double {UPIdQ'g   Dim curv As Double, conic As Double ,2kWj7H%7   Dim ok As Long ?2=c'%w7   uNRGbDMA=   Sub Main nK96A .B%p   u YH{4%       '用户输入对话框 `b%/.%]$       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 fO(.I           TextBox 220,21,40,21,.TextBox1 'default: 0 `$#64UZ>U1           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 #o^E1cI           OKButton 40,91,90,21 G3OQbqn           CancelButton 190,91,90,21 @wa/p`gj5w           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 JTs.NY <z           TextBox 220,49,40,21,.TextBox2 'default: 4 Dl"y|       End Dialog ?ke C       Dim dlg As UserDialog yNN2}\[.   _@RW7iP>       ok = Dialog (dlg) t(_XB|AKm   YInW)My.h       If ok=0 Then    'cancel button was pressed W%$p,^@S5           Print "Execution cancelled." <$=8'$T81           End TLV)mCZ       End If om/gk4S2   Hv IN'       'Assign accommodation and pupil diameter & use defaults if field left empty '$U"RP^(       If dlg.TextBox1 = "" Then b<7.^           A = 0           'Default accommodation i 2!{.*.       Else SZ1C38bd,.           A = CDbl(dlg.TextBox1) Ugs<WVp$       End If )1i)I?m   Jq; }q63:       If dlg.TextBox2 = "" Then f~U|flL^           pupilDiam = 4   'Default pupil diameter B}!n6j`       Else #/1Bam6           pupilDiam = CDbl(dlg.TextBox2) `kz_q/K       End If 8t 7hN?,t   M,{F/Yu       Print " " #".{i+3E       Print "Accommodation = " & A & " Diopters" +,KuYa{lu       Print "Pupil Diameter = " & pupilDiam & " mm" 4t+88 e    #?,cYh+       ' Calculate new parameters with accommodation UHg^F4>4       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness "?il07+w%   9\n}!{@i       Rant = 12.0 - 0.4*A                     'Radius of anterior lens UU !I@       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens # K-Q/*   rms&U)?       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens G.N 3R       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens  m$cM+   g 08 `=g       tlens = 3.767 + 0.04*A                  'Lens thickness  C[Fh^   w5|"cD#8A       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction WFdS#XfV   k |Lm;g       'Adjust parameters to account for accommodation VEn%_9(]   fU8;CZnx       '************************************************************************* ,L^L uw'7       'Aqueous thickness (Position of Lens) #z~oc^J^T       '************************************************************************* vSyN_AB?$       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 'nLv0.7*       GetCustomElement eID, entity ]#qdA(Kl   @s[bRp`gd       parID = FindFullName( "Geometry.Arizona Eye" ) q\/|nZO4   nOB ]?{X       ' Delete any shift(s) in z h'}5"m       count = 0 yw dNwNJ       While GetOperationCount(eID)>count %NBD^gF           GetOperation eID, count, op )I<.DN&           If op.Type="ShiftZ" Then K0v,d~+]               DeleteOperation eID,count 2sTyuH .               count=count-1 { u1t.+           End If ,=ICSS~9l           count=count+1 &O[o;(}mFI       Wend +g;G*EP 7*   -cW5v       'Set new shift in WV6vM()#!C       op.Type = "ShiftZ" 'X?`+2wK        op.val1 = taq 4VooU [Ka(       op.parent = parID $M8'm1R9       AddOperation eID, op `rcjZ^n       Print "Set aqueous humor thickness = " & taq-0.55 oT_,k}LIX   l5MxJ>?4%B       '************************************************************************* JDs<1@\       'Radius and conic constant of anterior lens W,<Vr2J[       '************************************************************************* x O)nS _I       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) t (1z+       GetConic eID, entity, curv, conic RDZq(rKc   eMF%!qUr       SetConic eID, entity, 1/Rant, CCant 99eS@}RC       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant (&B & V   x|Ei_hI-       '************************************************************************* J^W.TM&q$,       'Radius and conic constant of posterior lens E*ic9Za8`h       '************************************************************************* qle\c[UM5       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) <O*q;&9       GetConic eID, entity, curv, conic rd"]$_P8O   <ya3|ycnS       SetConic eID, entity, 1/Rpost, CCpost KW09qar       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost S38D cWIw   k`&mHSk-       '************************************************************************* $ey<8q zp       'Lens thickness (Position of posterior lens surface) igp4[Hj       '************************************************************************* OUs2)H61   PaZFM       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) m$o|s1t   wF%XM_M       ' Delete any z-shift(s) zso.? `85       count = 0 ?T^$,1-       While GetOperationCount(eID)>count S:5Nh^K           GetOperation eID, count, op dv,8iOL           If op.Type="ShiftZ" Then " qF&%&#r'               DeleteOperation eID,count kxdLJ_               count=count-1 a"v D+r7Ol           End If dRu@5 :BP           count=count+1 &o8\ $A       Wend prwyP   WOwIJrP       'Set new z-shift 7Ua Ll       op.Type = "ShiftZ" 1|gEY;Ru       op.val1 = tlens x=H*"L=       op.parent = parID hA"N&v~       AddOperation eID, op %xg"e O2x       Print "Set lens thickness = " & tlens <1@_MYo   h?TE$&CL?       '************************************************************************* u'N'<(\k       'Lens index of refraction sFGXW       '************************************************************************* q/Gy&8 K       eID = FindMaterial( "Lens" ) -aO3/Ik[q       GetModelMaterial eID, mat G,XFS8{%   8kqxr&,[       mat.Nd = nlens k}BNFv8       SetModelMaterial eID, mat 2x{3'^+l       Print "Set lens index of refraction = " & nlens r)b`3=   IUZsLNW       '************************************************************************* 2L,e\]2Z       'Pupil diameter yx-{}Yj^       '************************************************************************* +/Z:L$C6       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) O@ "6)/   `R; ct4-       'Adjust pupil diameter (trimming volume inner hole) [pOU!9v4   o30 PI       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" EatpORq   YZoH{p9f       ' Adjust pupil location to just in front of the lens }R J2\CP       parID = FindFullName( "Geometry.Arizona Eye" ) ,+q5e^P       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) bg$e80       count = 0 & XrV[d[>       While GetOperationCount(eID)>count hTy#Q.=           GetOperation eID, count, op =GLsoc-b           If op.Type="ShiftZ" Then ikY=}               DeleteOperation eID,count PvA%c<z               count=count-1 3rWqt           End If O4 }cv           count=count+1 (K2 p3M^       Wend sd=i!r)ya       op.Type = "ShiftZ" X/.|S57       op.val1 = taq-0.01 mMa7Eyaf       op.parent = parID }we"IqLb       AddOperation eID, op IP~g7`Y   fs`<x* }K       Print "Set pupil diameter = " & pupilDiam PCFm@S@Q   fCTjTlh       'Update AZ Eye subassembly Description &QE* V       eID = FindFullName( "Geometry.Arizona Eye" ) =,(Ba'       GetEntity eID, entity O'p7^"M       entity.Description = "Accommodation = " & A & "D" $i3/||T,9       SetEntity eID, entity vF*H5\ m<a   5v?6J#]2       Update myXp]=Sb?       Print "DONE!" CqF< BE        SR\#>Qwx_   End Sub QALMF rWH   K{0mb   如果屈光度是4，光瞳直径是4，则会输出如下数据： 2 OGg`1XX   U"ga0X5   Accommodation = 4 Diopters QXF>xZ~   Pupil Diameter = 4 mm zg^5cHP\   Set aqueous humor thickness = 2.81 v[~ U*#i   Set anterior lens radius = 10.4 and conic constant = -2.375869 OtnYv   Set posterior lens radius = -4.424557 and conic constant = -3.081019 A]>0lB   Set lens thickness = 3.927 7$w:~VZ   Set lens index of refraction = 1.42672 &18} u~M   Set pupil diameter = 4 K;YK[M1!   DONE!

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