Arizona眼睛模型

]52_p[hZ}<   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。 !J71[4t   NFSPw`f   模型 TRq~n7Y7C   $o @?D^   模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 ~*[}O)7#   Table 1. AZ眼睛模型的定义 uo{QF5z]   v[|iuOU   在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. hW},%   Ml3F\ fAW   光源 53T2w,?   OS9v.pz   多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 GS,pl9#V_   YW}/CwB   图1. 光源和提示信息使用 -12v/an]L7   UF{2Gx   除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 ^$L/Mv+   fBF}-{VX(   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。 {e@1,19   图2. 字母F光源的设定方法光 ZV U9t   <h}?0NA4   图3. 字母F在视网膜上位置点列图 +\ySx^vi   vLke,MKW   视网膜的散射 a@a1/3   us cR/d   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。 #SXXYh-e   5a`}DTB[Co   图4. 视网膜朗伯散射设定 'I~dJEW7   s_[?(Ip{   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。 Kaa*;T![   @$*c0. |z   图5. 视网膜重点采样规格设定 r%#qbsN   lV 9q;!/1   脚本 vuZ<'?Nm   b?$09,{0   内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： xpxm9ySwu   图6. 用户对话框的创建与编辑 <D^x6{}   图7. 用户对话框编辑器 xr/k.Fz   &zp5do;m   如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 QD<4(@c5|   余下的脚本计算与屈光度有关的所有参数。 Dk-L4FS   7S`H?},sR   分析 `R> O5Rv   T82_`u   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 (+_J0i t   图7. 字母F在视网膜上颜色分析 _~kcr5   fUXp)0O   脚本代码 ' 7A7HDJ   LJy'wl   Option Explicit     'Remove this to enable non-dimensioned variables to be used. T42g4j/l~   +Xp;T`,v   Dim entity As T_ENTITY fh^_=R(/   Dim op As T_OPERATION hvyN8We   Dim mat As T_MODELMATERIAL JdHc'WtS!|   Dim A As Double `O{Uz?#*x   Dim pupilDiam As Double 2z\F m/Z.   Dim eID As Long .%rR   Dim parID As Long .{-yveE   Dim count As Integer yFt7fdl2   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ["}A#cO652   Dim tlens As Double, nlens As Double iV&#5I   Dim curv As Double, conic As Double _&/Zab5   Dim ok As Long }'W^Ki$   4Le5Ms/   Sub Main Bkc-iC}F   i[pf*W0g       '用户输入对话框 pqSE|3*l       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 DBUwf1=qj           TextBox 220,21,40,21,.TextBox1 'default: 0 u-_$?'l;~           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 k)py\           OKButton 40,91,90,21 -z$0S%2?           CancelButton 190,91,90,21 pL@zZK0           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ]3xa{h~4           TextBox 220,49,40,21,.TextBox2 'default: 4 6bNW1]rD       End Dialog Q*.FUV&;       Dim dlg As UserDialog  >Gu0&   wIF ":'       ok = Dialog (dlg) Wts{tb   Wu( 8G       If ok=0 Then    'cancel button was pressed yU"G|Ex           Print "Execution cancelled." <o+ 7 U           End 4C%>/*%8>       End If k~f+LO   #sU~fq       'Assign accommodation and pupil diameter & use defaults if field left empty S I7B6c       If dlg.TextBox1 = "" Then :XSc#H4           A = 0           'Default accommodation Y:%)cUxA       Else e@=[+iJc           A = CDbl(dlg.TextBox1) Vb^s 'k       End If J'y N' 0   sjI[Vq       If dlg.TextBox2 = "" Then *\KMkx           pupilDiam = 4   'Default pupil diameter 51qIo4$       Else oks=|'&           pupilDiam = CDbl(dlg.TextBox2) d7J[.^\       End If |OZ>/l {   $|(|Qzi%       Print " " 4AOS}@~W       Print "Accommodation = " & A & " Diopters" YeC,@d[       Print "Pupil Diameter = " & pupilDiam & " mm" xY0QGQca   i?>> 9f@F       ' Calculate new parameters with accommodation >J3ja>Gw/       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ^HFU@/   "42$AaS       Rant = 12.0 - 0.4*A                     'Radius of anterior lens ;"Y;l=9_       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens v^W?o}W   #)A?PO2       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 9/daRq$       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens NzAtdcwR   rtL 9cw5       tlens = 3.767 + 0.04*A                  'Lens thickness Mc7<[a   90iW-"l+[       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 7e4tUAiuU   M.:@<S       'Adjust parameters to account for accommodation V\K m% vP   /P!X4~sTM       '************************************************************************* '%-xe3        'Aqueous thickness (Position of Lens) 8U2wH       '************************************************************************* $qtU       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) _RaVnMJKX4       GetCustomElement eID, entity 3cfZ!E~^kc   _`@Xy!Ye       parID = FindFullName( "Geometry.Arizona Eye" ) jaO#><f   OpbT63@L       ' Delete any shift(s) in z -{8Q= N       count = 0 [> &+*c       While GetOperationCount(eID)>count |t65#1           GetOperation eID, count, op ( X 'FQ           If op.Type="ShiftZ" Then Ec*--]j*c               DeleteOperation eID,count /cL9?k;o               count=count-1 ADyNNMcx           End If F 0BOhlK           count=count+1  Z|:_c       Wend <[3lV)~t   *M5$ h*;v       'Set new shift in RM^?&PM85       op.Type = "ShiftZ" lYZ@a4TA       op.val1 = taq =>:% n       op.parent = parID @%G'U&R{       AddOperation eID, op >^T,U0T])       Print "Set aqueous humor thickness = " & taq-0.55 >|_gT%]5   e1`)3-f       '************************************************************************* vN0L(B       'Radius and conic constant of anterior lens g~Nij~/       '************************************************************************* yA!3XUi       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 0K$WSGB?6j       GetConic eID, entity, curv, conic ]O[+c*|w   @dE 3       SetConic eID, entity, 1/Rant, CCant )-Mn"1ia       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant lk*0c{_L   o]|oAN9       '************************************************************************* iO?gF       'Radius and conic constant of posterior lens tv@Z5       '************************************************************************* } Jdh^t.       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) f#;ubfi"z       GetConic eID, entity, curv, conic zfP[1   Lt;.Nw       SetConic eID, entity, 1/Rpost, CCpost ~51kiQW       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost U5On-T5   JO&;bT<       '************************************************************************* iJCY /*C}       'Lens thickness (Position of posterior lens surface) q*F~~J!P       '************************************************************************* Qe @A5#   T.R>xd`9 "       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) >%n8W>^^4   j#LV7@H.e?       ' Delete any z-shift(s) q(Z B.       count = 0 e-%7F]e       While GetOperationCount(eID)>count 1*!c X           GetOperation eID, count, op zH=/.31Q           If op.Type="ShiftZ" Then `r~`N`o5A               DeleteOperation eID,count ]Efh(Gb]               count=count-1 pjX%LsX\           End If ~zE 1'           count=count+1 Q8;x9o@p       Wend 0^<Skm27"   G _2gKkIK-       'Set new z-shift jpYw#]Q       op.Type = "ShiftZ" @b::6n/u       op.val1 = tlens a2cx       op.parent = parID =RW* %8C       AddOperation eID, op XI%RneuDr:       Print "Set lens thickness = " & tlens r%g <hT 8   m{:"1]       '************************************************************************* CU#L *kz       'Lens index of refraction ~4 MtDf       '************************************************************************* 2p$n*|T&c       eID = FindMaterial( "Lens" ) dl*_ m3T       GetModelMaterial eID, mat m6bWmGnGC   hV3,^#9o       mat.Nd = nlens dJdD"xj       SetModelMaterial eID, mat ]97Xu_       Print "Set lens index of refraction = " & nlens 8Ehy9<   7.7Cluh5,       '************************************************************************* SE-!|WR       'Pupil diameter lF;ziF       '************************************************************************* Ur_S [I       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) "J]f0m=   &#.x)>f       'Adjust pupil diameter (trimming volume inner hole) \S=XIf   a-T*'F       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 5z9r S<   ~&wXXVK3       ' Adjust pupil location to just in front of the lens jGk7=}nw       parID = FindFullName( "Geometry.Arizona Eye" ) bjM-Hd/K       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ppwd-^f3j       count = 0 |QnUK5D$       While GetOperationCount(eID)>count D 7Gd %           GetOperation eID, count, op ?Ia4H           If op.Type="ShiftZ" Then lEO?kn.:z               DeleteOperation eID,count r\A@&5#q               count=count-1 C$]5l;`           End If 7j@^+rkr3f           count=count+1 Tjd&^m       Wend M*g2VyZ       op.Type = "ShiftZ" "_nX5J9       op.val1 = taq-0.01 c+szU}(f6(       op.parent = parID y-E1]4?})       AddOperation eID, op $?H]S]#|}.   P\D[n-&       Print "Set pupil diameter = " & pupilDiam pd=7^"[};   3mpP|b"       'Update AZ Eye subassembly Description 98D{{j92       eID = FindFullName( "Geometry.Arizona Eye" ) }U2[?       GetEntity eID, entity '4J&Gpx       entity.Description = "Accommodation = " & A & "D" EG F:xl       SetEntity eID, entity !&@2   Ix( 6       Update D"`%|`O       Print "DONE!" -(6eVI        Nawp t%   End Sub }R`8h&J   b cC\   如果屈光度是4，光瞳直径是4，则会输出如下数据： "AT&!t[J   YH6snC$u   Accommodation = 4 Diopters 5/Ydv RB67   Pupil Diameter = 4 mm  ]a78tTi   Set aqueous humor thickness = 2.81 a^@+%?X   Set anterior lens radius = 10.4 and conic constant = -2.375869 ceqFQ   Set posterior lens radius = -4.424557 and conic constant = -3.081019 cge-'/8w%   Set lens thickness = 3.927  =Ov9Kf   Set lens index of refraction = 1.42672 }j&O/Up   Set pupil diameter = 4 'g. :MQ8   DONE!

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