Arizona眼睛模型

]z%9Q8q'   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。 ?yb{DZ46   `7A@\Ha3   模型 z~5'p(|@f   el%Qxak`"   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。 u5ygbCm   Table 1. AZ眼睛模型的定义 gD\}CxtG   (Vv]:Y]   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. 5S?yj   3Cl9,Z"&6$   光源 8gxLL59   \nWpV7TSN   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。 "lZ<bG   2Qj)@&zKe#   图1. 光源和提示信息使用 c53`E U   UXJl;Mb   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。 )]R?v,9*D   YLo$n   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。 }b(e   图2. 字母F光源的设定方法光 S@)bl   }"Cn kg   图3. 字母F在视网膜上位置点列图 U*TN/6Qy.   [ _$$P*   视网膜的散射 1%`:8   QR'g*Bro   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。 QEKFuY<E+   Biy 9jIWI   图4. 视网膜朗伯散射设定 ($ W 5fbu   lz 6 Aj   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。 $ZO<8|bW   &L]*]Xz;   图5. 视网膜重点采样规格设定 }C1wfZ~F~   O;BPd:<   脚本 sD+G+   9(WC#-,   内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： |Z e}bM=N   图6. 用户对话框的创建与编辑 B aAb4{   图7. 用户对话框编辑器 *Rh .s!@4   9A(K_d-!H   如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 I "2FTGA   余下的脚本计算与屈光度有关的所有参数。 P0z{R[KBH   fZfiiE~7J   分析 X~3P?O]kFv   iGk{8Da<   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 QB,ad    图7. 字母F在视网膜上颜色分析 % cdP*   :<8V2   脚本代码 #>B1$(@   , ~X;M"U   Option Explicit     'Remove this to enable non-dimensioned variables to be used. ?/MXcI(   )du{ZWr   Dim entity As T_ENTITY Ue:T3jp3%   Dim op As T_OPERATION B31-<w   Dim mat As T_MODELMATERIAL &X,)+b=   Dim A As Double zEfD{I   Dim pupilDiam As Double ~|C1$.-   Dim eID As Long D.R   Dim parID As Long |qDfFGYf   Dim count As Integer #!,`E U   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double {OrE1WHB   Dim tlens As Double, nlens As Double N-YZ0/c   Dim curv As Double, conic As Double NV4W2thYo   Dim ok As Long !!%nl_I (   ldvxYq<:   Sub Main jdf)bO(9#   WC*:\:mh       '用户输入对话框 Q]UYG(       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 f+Li'?           TextBox 220,21,40,21,.TextBox1 'default: 0 RmV/wY           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 B^~Bv!tHWr           OKButton 40,91,90,21 vcU\xk")           CancelButton 190,91,90,21 z2 V8NUn           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 pY>-N           TextBox 220,49,40,21,.TextBox2 'default: 4 A;a(n\Sy       End Dialog c.A/{a       Dim dlg As UserDialog G$9|aaf`1#   "sX?wTag       ok = Dialog (dlg) Rbc2g"]    aq/Y}s?       If ok=0 Then    'cancel button was pressed WTv\HI2X !           Print "Execution cancelled." V?dK*8s           End ]J=)pDrk       End If <?7,`P:h[   R&_\&:4f       'Assign accommodation and pupil diameter & use defaults if field left empty Rn_W|"       If dlg.TextBox1 = "" Then -U;LiO;N           A = 0           'Default accommodation ]l7\Zq       Else YkAWKC Oni           A = CDbl(dlg.TextBox1) 02#Iip3t       End If eEGcio}_I9   a;T[%'in       If dlg.TextBox2 = "" Then 64rk^Um           pupilDiam = 4   'Default pupil diameter "M0l;       Else #L= eK8^e           pupilDiam = CDbl(dlg.TextBox2) %R*vSRG/U       End If )u)$ `a   !Fg4Au       Print " " {2gd4[:       Print "Accommodation = " & A & " Diopters" C5PBfn<j       Print "Pupil Diameter = " & pupilDiam & " mm" pW--^aHu   O0(Q0Ko       ' Calculate new parameters with accommodation yO,`"Dc_0       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ~TFYlV   [xp,&       Rant = 12.0 - 0.4*A                     'Radius of anterior lens %x8`fm       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens a(DZGQ-as   DcR}pQ(e       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens S{(p<%)[       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens j484b2uj1   X8SRQO^       tlens = 3.767 + 0.04*A                  'Lens thickness O:=|b]t   |}p}`Mb)a       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction +\8krA   ._MAHBx+G       'Adjust parameters to account for accommodation , 64t   /b:t;0G       '************************************************************************* M$4=q((0       'Aqueous thickness (Position of Lens) Ao,!z       '************************************************************************* [aM'       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) {+6D-rDw       GetCustomElement eID, entity "3i80R\w`F   : {WrS       parID = FindFullName( "Geometry.Arizona Eye" ) LQ(5D_yG.   @-&(TRbZo       ' Delete any shift(s) in z "(\) &G       count = 0 ^g-t#O lD?       While GetOperationCount(eID)>count  c(V=.+J           GetOperation eID, count, op UUMdZ+7           If op.Type="ShiftZ" Then 9ze|s^               DeleteOperation eID,count ?X#/1X%u:               count=count-1 hUT^V(           End If ^2C /!Y<           count=count+1 iA3>X-x        Wend euj8p:+X   Z 5)_B,E:X       'Set new shift in 'LbeL1ca       op.Type = "ShiftZ" GKyG #Fl       op.val1 = taq 4OOn,09       op.parent = parID Gl8&FrR       AddOperation eID, op (e8G (       Print "Set aqueous humor thickness = " & taq-0.55 o`\.I&Ij   )o9Q5Lq       '************************************************************************* PwB g       'Radius and conic constant of anterior lens _))I.c=v       '************************************************************************* 5`E`Kb+@       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) h^A3 0f_x       GetConic eID, entity, curv, conic Z<ajET`)   gM3]%L_       SetConic eID, entity, 1/Rant, CCant )W1(tEq59       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant JS/M~8+Et   @1qdd~B}       '************************************************************************* Jh43)#G-       'Radius and conic constant of posterior lens 7Y32p'       '************************************************************************* (/SGT$#8       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) f{igW?Ho       GetConic eID, entity, curv, conic OpK.Lsd0y   I%9bPQ       SetConic eID, entity, 1/Rpost, CCpost xEVLE,*?>       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost `s`C{|wv   3duG.iUlL       '************************************************************************* fimb]C I|x       'Lens thickness (Position of posterior lens surface) ^Ue0mC7m       '************************************************************************* \9]I#Ih}M   Z6Nj<2u2       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ]^:hyOK   Xb]=:x(       ' Delete any z-shift(s) ` l>93A       count = 0 y !<'r g       While GetOperationCount(eID)>count ~^I\crx,U%           GetOperation eID, count, op q]6_ rY.           If op.Type="ShiftZ" Then X*sr               DeleteOperation eID,count iW|s|1mh3               count=count-1 |1(rr%           End If =n-z;/NL           count=count+1 l#D-q/k?       Wend JFM"ii{8   "v(G7*2       'Set new z-shift @iU%`=ziz       op.Type = "ShiftZ" &P 8!]:       op.val1 = tlens ~->Hlxze'K       op.parent = parID W.A1m4l58R       AddOperation eID, op E@w [&#       Print "Set lens thickness = " & tlens 8p (!]^z   OlMBMUR:       '************************************************************************* ! FNf>z+       'Lens index of refraction b'velj3A       '************************************************************************* 'nRp}s1^[       eID = FindMaterial( "Lens" ) [E>R.Oe       GetModelMaterial eID, mat ;rd6ko   [}>#YPZ       mat.Nd = nlens :GQUM6       SetModelMaterial eID, mat S|"Fgoj r       Print "Set lens index of refraction = " & nlens ZCm1+Y$   >']+OrQH       '************************************************************************* BlXX:aZv       'Pupil diameter a{h%DpG       '************************************************************************* $ye^uu;Z       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 4d!S#zx   f1A_`$>       'Adjust pupil diameter (trimming volume inner hole) nV' 3sUvR#   OI+E (nA       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" <^xfcYx\   BBcj=]"_       ' Adjust pupil location to just in front of the lens KiQ(XNx       parID = FindFullName( "Geometry.Arizona Eye" ) >):m-I       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) MDk*j,5V       count = 0 Hk,lX r       While GetOperationCount(eID)>count /Zc#j^_           GetOperation eID, count, op kLJlS,nh\r           If op.Type="ShiftZ" Then R1}IeeZO?&               DeleteOperation eID,count OR]T`meO               count=count-1 o,CBA;{P           End If [FGgkd}           count=count+1 O@s{uZ|A6       Wend Q:mZ" i5       op.Type = "ShiftZ" 1!!\+ c2*       op.val1 = taq-0.01 <yZP|_        op.parent = parID j" )FaIM       AddOperation eID, op l]H0g[   lX"bN=E?!       Print "Set pupil diameter = " & pupilDiam AM'gnP>   ?w*yW;V`       'Update AZ Eye subassembly Description i3\~Qj;1       eID = FindFullName( "Geometry.Arizona Eye" ) 1]j^d       GetEntity eID, entity x=.tiM{#       entity.Description = "Accommodation = " & A & "D" 8W;2oQN7       SetEntity eID, entity %swR: B v   e&0N K8&#+       Update V$(/0mQV(       Print "DONE!" ZRnL_z~        G Mb(10T`   End Sub 6UlF5pom   e2c1pgs&+   如果屈光度是4，光瞳直径是4，则会输出如下数据： tjj^O%SV<   r0\?WoF2C   Accommodation = 4 Diopters }p=g*Zo*C;   Pupil Diameter = 4 mm M'q'$)e   Set aqueous humor thickness = 2.81 qK?$=h.   Set anterior lens radius = 10.4 and conic constant = -2.375869 jq(qo4~;   Set posterior lens radius = -4.424557 and conic constant = -3.081019 DR@1z9 a   Set lens thickness = 3.927 j$vK<SF   Set lens index of refraction = 1.42672 1}}>Un`U5,   Set pupil diameter = 4 yxwWj>c   DONE!

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