Arizona眼睛模型

\f  LBw0   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。 kC0!`$<2f)   W% [ 5~N   模型 M<)2   P Cf|^X#B   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。 8zCAy@u   Table 1. AZ眼睛模型的定义 FCWphpz   Cg Sdyg@   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. w(j9[   xD=D *W   光源 agYKaM1N   z! +<m<   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。 yjq )}y,tF   nf4P2<L!   图1. 光源和提示信息使用 #+;=ijyF   ttnXEF   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。 4.'EEuRw\}   ;]Aa   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。 ,&=`T7i   图2. 字母F光源的设定方法光 bwJi[xF   v#|c.<].   图3. 字母F在视网膜上位置点列图 N::;J   DVJc-.x8   视网膜的散射 )9r%% #   Ic K=E]p   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。 h+UscdUl   @:&+wq_>A^   图4. 视网膜朗伯散射设定 fhmr*E'J   F47n_JV!d   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。 zq.&Mw ?   =T)2wcXBB   图5. 视网膜重点采样规格设定 PHvjsA%"   {*<C!Qg   脚本 aA`q!s.%A   Lf #G?]@   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： Y14R"*t~   图6. 用户对话框的创建与编辑 (;&?B.<\:   图7. 用户对话框编辑器 kZ9<j+.   SN(=e#ljE   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。 nY9qYFw   余下的脚本计算与屈光度有关的所有参数。 :dN35Y]a   \&5@yh   分析 j/D)UWkR   `M ygDG+u   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 ^Nw]'e3   图7. 字母F在视网膜上颜色分析 b@/ON}gX   k8e"5 he   脚本代码 rR@n> Xx   ~8t}*oV    Option Explicit     'Remove this to enable non-dimensioned variables to be used. @/~k8M/   ]B3FTqR{i   Dim entity As T_ENTITY i\;&CzC:   Dim op As T_OPERATION `^L<db^A   Dim mat As T_MODELMATERIAL 6 ]PM!6   Dim A As Double 3:joSQa   Dim pupilDiam As Double {(}w4.!   Dim eID As Long MLBg_<   Dim parID As Long mN{ajf)@   Dim count As Integer _qt;{,t   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double `B\KS*Gya#   Dim tlens As Double, nlens As Double =6<w'>   Dim curv As Double, conic As Double T[h}A"yK;   Dim ok As Long R}wwC[{   7tl)4A6   Sub Main k;fnC+Y$s   $sc8)d\B       '用户输入对话框 O3C)N I\i       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 j+13H +dN           TextBox 220,21,40,21,.TextBox1 'default: 0 }8V;s-1           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 I"Q9W|J_&           OKButton 40,91,90,21 *T>#zR{           CancelButton 190,91,90,21 {`K]sa7`           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Gp ^ owr           TextBox 220,49,40,21,.TextBox2 'default: 4 /[|}rqX(       End Dialog }`9fZK{. @       Dim dlg As UserDialog ;%rs{XO9   Eo {1y       ok = Dialog (dlg) ZU|V+yT   X[~f:E[1J       If ok=0 Then    'cancel button was pressed 1!;"bHpk           Print "Execution cancelled." R5NRCI           End C*{15!d:G       End If + %e%UF@   a(x.{}uG,       'Assign accommodation and pupil diameter & use defaults if field left empty _yxe2[TD       If dlg.TextBox1 = "" Then n^JUZ8           A = 0           'Default accommodation 0l(E!d8& '       Else ]m/@wW9           A = CDbl(dlg.TextBox1) \2gvp6       End If G {pP}   } `>J6y9       If dlg.TextBox2 = "" Then ZM-/n>           pupilDiam = 4   'Default pupil diameter [al(>Wr9       Else =0s`4Y"+           pupilDiam = CDbl(dlg.TextBox2) %qNj{<&       End If F;?TR[4!k   1&8j3"       Print " " 2 [8fFo>       Print "Accommodation = " & A & " Diopters" ,<;l"v(       Print "Pupil Diameter = " & pupilDiam & " mm"  +eDN,iv   ^B<PD]       ' Calculate new parameters with accommodation {hs2?#p       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Ypn%[sSOp   fz<|+(_>J       Rant = 12.0 - 0.4*A                     'Radius of anterior lens >%n8W>^^4       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens u:Af HZ   %67G]?EXB       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens [Q7->Wo|S:       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Eo7 _v   zH=/.31Q       tlens = 3.767 + 0.04*A                  'Lens thickness r6oX6.c   Yn I M-       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Q QsVIHA   7GBZA=J       'Adjust parameters to account for accommodation nJldz;   H7z>S G0       '************************************************************************* .^[fG59       'Aqueous thickness (Position of Lens) Pg*?[^*       '************************************************************************* a2cx       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) nu46 9       GetCustomElement eID, entity XI%RneuDr:   RQj`9F       parID = FindFullName( "Geometry.Arizona Eye" ) m{:"1]   CU#L *kz       ' Delete any shift(s) in z ~4 MtDf       count = 0 (B>yaM#5       While GetOperationCount(eID)>count dl*_ m3T           GetOperation eID, count, op ]/aRc=Gn           If op.Type="ShiftZ" Then VL_)]LR*)               DeleteOperation eID,count e/]O<,*               count=count-1 WX%h4)z*           End If Eonq'Re$           count=count+1 wq:b j=j       Wend rt5oRf:wY   6pM"h5hA       'Set new shift in F9m2C'U       op.Type = "ShiftZ" [<en1       op.val1 = taq _9Dn\=g       op.parent = parID Ek"YM[       AddOperation eID, op ~=`f]IL       Print "Set aqueous humor thickness = " & taq-0.55 =gMaaGg p,   FSW3'       '************************************************************************* cwH,l$       'Radius and conic constant of anterior lens FX7Cjo #=R       '************************************************************************* 'sm[CNzS       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) %-@'CNP       GetConic eID, entity, curv, conic ax-=n(    &_Cxv8       SetConic eID, entity, 1/Rant, CCant +L`V [;       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant SjZd0H0   BlkSWW/       '************************************************************************* bh= \       'Radius and conic constant of posterior lens (A7T} znG       '************************************************************************* a6;gBoV       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ]}nu9z<       GetConic eID, entity, curv, conic L/qZ ;{   RtW4n:c       SetConic eID, entity, 1/Rpost, CCpost r:fwrC       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Nbgp_:{   H"Q(2I       '************************************************************************* 2"T8^r|U       'Lens thickness (Position of posterior lens surface) S9OxI$6Y       '************************************************************************* 3M}AxEu   IL!BPFG w       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) /'-:=0a   umJay />       ' Delete any z-shift(s) 1k!D0f3qb       count = 0 y\[L?Rmd       While GetOperationCount(eID)>count mcvDxjk,h           GetOperation eID, count, op NY~ dM\           If op.Type="ShiftZ" Then ! a86iHU               DeleteOperation eID,count l9]o\JFXk               count=count-1 YH6snC$u           End If aF D="Zh           count=count+1 a^@+%?X       Wend ceqFQ   fy9uLl}h       'Set new z-shift  =Ov9Kf       op.Type = "ShiftZ" ^it4z gx@       op.val1 = tlens 'g. :MQ8       op.parent = parID Bfbl#ZkyL       AddOperation eID, op g;$E1U=R-E       Print "Set lens thickness = " & tlens q A.+U:I8   ^%-NPo<       '************************************************************************* )URwIe{       'Lens index of refraction i:g{{Uuv       '************************************************************************* 1UC2zM"       eID = FindMaterial( "Lens" ) C#Y,r)l       GetModelMaterial eID, mat D[V`^CTu   ym HKcQ       mat.Nd = nlens <inl{CX/       SetModelMaterial eID, mat LOe4c0C6Ca       Print "Set lens index of refraction = " & nlens :RPVT,O}   ;F|jG}M "       '************************************************************************* $Xf~# uH       'Pupil diameter N[>:@h       '************************************************************************* ggMUdlU       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) i"/r)>"b   wtlB       'Adjust pupil diameter (trimming volume inner hole) AD(xaQ&T   x 96}#0'       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" fH&zR#T7U4   D 4d]3|/T       ' Adjust pupil location to just in front of the lens S45'j(S=       parID = FindFullName( "Geometry.Arizona Eye" ) /({P1ti:C       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) sbzeY1       count = 0 JW-|<CJ       While GetOperationCount(eID)>count #&k8TY           GetOperation eID, count, op ?b 5H 2W           If op.Type="ShiftZ" Then FWIih5 3`               DeleteOperation eID,count /=b St               count=count-1 AYt*'Zeg!s           End If O(o dNQy~           count=count+1 " l.!Ed       Wend /GyEVCc       op.Type = "ShiftZ" .6LS+[        op.val1 = taq-0.01 ^mAJ[^%       op.parent = parID )q^(T1       AddOperation eID, op STw oYn   %,XI]+d       Print "Set pupil diameter = " & pupilDiam 1p~5h(jI   %U-Qsy8|D)       'Update AZ Eye subassembly Description jBS'g{y-!       eID = FindFullName( "Geometry.Arizona Eye" ) <H!O:Mf_p       GetEntity eID, entity f:S}h-AL&       entity.Description = "Accommodation = " & A & "D" 1PmX."a       SetEntity eID, entity ; > 5,   lelMt=       Update gbJG`zC>U       Print "DONE!" Y!F!@`%G        Xt\Dy   End Sub 'g2vX&=$A   NfOp=X?Y   如果屈光度是4，光瞳直径是4，则会输出如下数据： L(;.n>/   \,hrk~4U;(   Accommodation = 4 Diopters X`D+jiQ(f   Pupil Diameter = 4 mm (NPxab8e*   Set aqueous humor thickness = 2.81 !KAsvF,j   Set anterior lens radius = 10.4 and conic constant = -2.375869 3Mur*tj#   Set posterior lens radius = -4.424557 and conic constant = -3.081019 G#|Hu;C6"   Set lens thickness = 3.927 RU7!U mf   Set lens index of refraction = 1.42672 J,9%%S8/C   Set pupil diameter = 4 vsc&Ju%k   DONE!

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