Arizona眼睛模型

&!N5}N&   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。 fP&F$"o8   vD[@cm   模型 T9*\ITA   q4xB`G   模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 | Rhx&/   Table 1. AZ眼睛模型的定义 ^G~W}z?-   n &r-   在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. TEh]-x`   !jU<(eY   光源 Z?ZcQ[eC   U#Wc!QN-t   多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。  &oWWc$   w>IkC+.?   图1. 光源和提示信息使用 pyT+ba#   lqF{Y<l   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。 p<Ah50!B   )gmDxD ^C   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。 !6@xX08z   图2. 字母F光源的设定方法光 Bag2sk    +h9UV   图3. 字母F在视网膜上位置点列图 @1*lmFq'kV   &M6)-V4   视网膜的散射 r{YyKSL1*K   &VY;Al   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。 ngsa x1xO   xGk@BA=0<   图4. 视网膜朗伯散射设定 >BrxJw#M   (e=ksah3>   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。 JjfNH ~   d;mQ=k 1   图5. 视网膜重点采样规格设定 #_2V@F+,   Jtd@8fVi   脚本 U"%k4]:A   ~H@':Mms.h   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： ,^26.p$   图6. 用户对话框的创建与编辑 d=oOMXYa    图7. 用户对话框编辑器 ]1)@.b;QR   ,\+tvrR4X   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。 cuq7eMG6z   余下的脚本计算与屈光度有关的所有参数。 D8m?`^Zz   #7lkj:j4   分析 **_VNDK+   %f6l"~y   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 &I'~:nWpt   图7. 字母F在视网膜上颜色分析 3[SN[faS   Yo| H`m,   脚本代码 sx*1D9s_   I;P?P5H   Option Explicit     'Remove this to enable non-dimensioned variables to be used. v 0rX/ mj   AA>5h<NM   Dim entity As T_ENTITY .Z%7+[   Dim op As T_OPERATION F|xXMpC.f   Dim mat As T_MODELMATERIAL rJ\A)O+Mq(   Dim A As Double 7 aDI6G   Dim pupilDiam As Double :e+GtN?   Dim eID As Long <e/O"6='Z   Dim parID As Long ]DmqhK`   Dim count As Integer QAygr4\X^   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double '3+S5p8   Dim tlens As Double, nlens As Double RVI],O   Dim curv As Double, conic As Double JO :m: M   Dim ok As Long GdG %=+   LaN4%[;X1-   Sub Main ry~3YYEMI0   Cf`UMQ a       '用户输入对话框 <i]%T~\Af)       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 lz{>c.Ll[           TextBox 220,21,40,21,.TextBox1 'default: 0 MYN1zYT6j           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 @'C)ss=kj           OKButton 40,91,90,21 2i,Jnv=sR           CancelButton 190,91,90,21 ^jf$V#z0/           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 WCR+ZXI?1           TextBox 220,49,40,21,.TextBox2 'default: 4 *k+QX        End Dialog ec=4L@V*       Dim dlg As UserDialog _xUhDu%   g-+p(Ll|       ok = Dialog (dlg) Q96g7[   5Qy,Pkje       If ok=0 Then    'cancel button was pressed (a^F`#]           Print "Execution cancelled." \F1nEj           End 3g-}k       End If D|=QsWZI   Y Nq<%i!>       'Assign accommodation and pupil diameter & use defaults if field left empty 5+ fS$Q       If dlg.TextBox1 = "" Then l_,8_u7G           A = 0           'Default accommodation N"E\o,_       Else tmb0zuJ&C!           A = CDbl(dlg.TextBox1) zEO 9TuBO       End If 'kx{0J?   fcw\`.        If dlg.TextBox2 = "" Then TS UN(_XGW           pupilDiam = 4   'Default pupil diameter *Gu=O|Mm       Else ?|s[/zPS=           pupilDiam = CDbl(dlg.TextBox2) o,aI<5"       End If ?nt6vqaV   mY`b|cS3p$       Print " " &Q&$J )0       Print "Accommodation = " & A & " Diopters" .Bi7~*N       Print "Pupil Diameter = " & pupilDiam & " mm" <n6/np!   6?,r d       ' Calculate new parameters with accommodation dDm<'30?*v       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ?C $_?Qi   Pv0+`>):       Rant = 12.0 - 0.4*A                     'Radius of anterior lens ||!k 3t#<       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ,9A[o`b   Q kF-}P%       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens As)-a5!       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens MaM s(   }>0UaK       tlens = 3.767 + 0.04*A                  'Lens thickness P}VD}lEyO   ]\_4r)cN<n       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ol:_2G2xQ   nZ%<2       'Adjust parameters to account for accommodation g8qN+Gg   Q0 ^?jh       '************************************************************************* YEZ"BgUnbp       'Aqueous thickness (Position of Lens) 0&mz'xra       '************************************************************************* !MGQ+bD6       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5,mb]v0k       GetCustomElement eID, entity 5TnECk   `q5*VqIhs       parID = FindFullName( "Geometry.Arizona Eye" ) FijzO   6'Lij&,f?{       ' Delete any shift(s) in z a{-}8f6       count = 0 JgxOxZS`@       While GetOperationCount(eID)>count |5FyfDaFBX           GetOperation eID, count, op &j>`H:           If op.Type="ShiftZ" Then TI*uNS;-               DeleteOperation eID,count ;ga~ae=Fg               count=count-1 bF}~9WEa           End If #cmj?y()           count=count+1 H~$a6T"&       Wend ey Cg *   zb9$       'Set new shift in "1l d4/       op.Type = "ShiftZ" w-\GrxlbX       op.val1 = taq Qb SX'mx<       op.parent = parID +1cK (Si       AddOperation eID, op Z-/ E$j       Print "Set aqueous humor thickness = " & taq-0.55 W{0<ro`   $MP'j9-S?       '************************************************************************* 4K4?Q+?       'Radius and conic constant of anterior lens +:^tppg       '************************************************************************* ^WVr@6       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) hx:x5L>       GetConic eID, entity, curv, conic gMgbqGF)   ?p}m[9@       SetConic eID, entity, 1/Rant, CCant P [gqv3V       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ,rG$JCS'KQ   3 D+dM0wM       '************************************************************************* <)"Mi}Q[)p       'Radius and conic constant of posterior lens Ao=.=0os       '************************************************************************* +='.uc_       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) %*Y:Rm'>       GetConic eID, entity, curv, conic !qy/'v4   c"fnTJXr79       SetConic eID, entity, 1/Rpost, CCpost a|66[       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost *,z__S$Q)   ^Dd$8$?[       '************************************************************************* 'GNT'y_       'Lens thickness (Position of posterior lens surface) <S5Am%vo       '************************************************************************* Pirc49c   nKV1F0-       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) #,$d!l @   Q;`#ujxL       ' Delete any z-shift(s) 4GaF:/       count = 0 +e4o~p       While GetOperationCount(eID)>count ]3C7guWz           GetOperation eID, count, op UB=I>           If op.Type="ShiftZ" Then  &grT}               DeleteOperation eID,count A<AZs~f               count=count-1 up`!r;5-           End If LiiQ;x           count=count+1 M"5,8Q`PkI       Wend Ga$+x++'*   @-)?2CH[8       'Set new z-shift k%Jw S_F       op.Type = "ShiftZ" ,GGr@})       op.val1 = tlens a B%DIH,       op.parent = parID p)Z$q2L       AddOperation eID, op YW0UIO       Print "Set lens thickness = " & tlens FhS:.   vMDV%E S1t       '************************************************************************* Oe*emUX7       'Lens index of refraction kW5g]Q       '************************************************************************* "ifYy>d       eID = FindMaterial( "Lens" ) fY$M**/,       GetModelMaterial eID, mat b`fPP{mG   a\aJw[d{       mat.Nd = nlens 8 <EE4y       SetModelMaterial eID, mat dz&8$(f,       Print "Set lens index of refraction = " & nlens X.bNU   LEWeybT       '************************************************************************* $_% a=0       'Pupil diameter eDgRYa9\       '************************************************************************* jL>IX`,+6       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) n<uF9N<    9}jF]P*Q       'Adjust pupil diameter (trimming volume inner hole) PiP\T.XANa   uI!rJc>TX       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Kbrb;r59   m "h{HgJd       ' Adjust pupil location to just in front of the lens p,Qr9p3y       parID = FindFullName( "Geometry.Arizona Eye" ) 6/Q'o5>NL:       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) tc.R(F96       count = 0 r|:i: ii       While GetOperationCount(eID)>count E~3wdOZv1           GetOperation eID, count, op kR3g,P{L           If op.Type="ShiftZ" Then S{7A3 x'B               DeleteOperation eID,count Cpz'6F^oP               count=count-1 xJ:15eDC           End If {+F/lN@           count=count+1 B#N(PvtE       Wend 0V@u]       op.Type = "ShiftZ" |^[]Oy=       op.val1 = taq-0.01 mADq_`j       op.parent = parID 4 >at#Zc       AddOperation eID, op d dkh*[   x$tx!%,)/S       Print "Set pupil diameter = " & pupilDiam s =h   yO;r]`j0       'Update AZ Eye subassembly Description [kM)K'-       eID = FindFullName( "Geometry.Arizona Eye" ) d<r=f"       GetEntity eID, entity RtwlPz<~S       entity.Description = "Accommodation = " & A & "D" w$MFCJ:p&       SetEntity eID, entity */;[ -9   n*D-01vYP       Update ) wtVFG       Print "DONE!" zxTcjC)y        (sHqzWh   End Sub <C`qJP-   AKk6kI8F   如果屈光度是4，光瞳直径是4，则会输出如下数据： dbQUW#<Q   R@N I   Accommodation = 4 Diopters 8D@H4O.   Pupil Diameter = 4 mm rlEEf/m:   Set aqueous humor thickness = 2.81 ,u8)g;8s   Set anterior lens radius = 10.4 and conic constant = -2.375869 ze@NqCF   Set posterior lens radius = -4.424557 and conic constant = -3.081019 X `JWYb4   Set lens thickness = 3.927 >RZ]t[)y   Set lens index of refraction = 1.42672 ViIt'WX   Set pupil diameter = 4 OOA%NKV   DONE!

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