Arizona眼睛模型

\MfR #k0   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。 M0Lon/%   PY[Sz=[   模型 w2.qT+;v   ,oC={^l{   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。 TXA. 6e   Table 1. AZ眼睛模型的定义 YhEiN. ~   1!K!oY   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. FEge +`{,   W ]a7&S   光源 Y+|L3'H   -HO6K)ur   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。 \Sz4Gr0g3Z   KteZK.+#:   图1. 光源和提示信息使用 F! |TW6)gv   DMy4"2 o   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。 |:!EHFr   JrY"J]/   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。 de3yP,   图2. 字母F光源的设定方法光 3(oZZz   gEcnn.(S   图3. 字母F在视网膜上位置点列图 |6\FI?   }dV9%0s!   视网膜的散射 AJJ%gxqGq   ^EnNbFI   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。 p{\qSPK   Sn{aHH   图4. 视网膜朗伯散射设定 l4R<`b\ Jt   iKR8^sj7S   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。 oyi7YRvwd   p,_6jdz   图5. 视网膜重点采样规格设定 f(w#LuW<   /6Jy'"+'0   脚本 j]cXLY   v@}1WGY   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： 2zmQp   图6. 用户对话框的创建与编辑 N]O{T_5-0   图7. 用户对话框编辑器 %zIl_/s   //`cwnjp   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。 +=,4@I%   余下的脚本计算与屈光度有关的所有参数。 "(HA9:   Q]2sj:   分析 wfU&{7yt   q9g[+*9]$   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 \E ? iw.}   图7. 字母F在视网膜上颜色分析 @8 oDy$j   EL2hD$   脚本代码 KV)Hywl`   O9Jx%tolF%   Option Explicit     'Remove this to enable non-dimensioned variables to be used. -Ib+#pX   =: v><   Dim entity As T_ENTITY G{&yzHAuae   Dim op As T_OPERATION ci{9ODN   Dim mat As T_MODELMATERIAL 6x (L&>F   Dim A As Double priT7!   Dim pupilDiam As Double ]IbPWBX   Dim eID As Long D=q;+,Pc   Dim parID As Long Tvksf!ba   Dim count As Integer J;Z>fAE7   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double &?5{z \;1"   Dim tlens As Double, nlens As Double 8-y: ==C   Dim curv As Double, conic As Double S,)|~#5x   Dim ok As Long :<WQ;q   -KU)7V   Sub Main J6^Ct   0 8d_DC R       '用户输入对话框 6iV"Tl{z-       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ?( dYW7S           TextBox 220,21,40,21,.TextBox1 'default: 0 35N/v G0           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 %M0mwty]           OKButton 40,91,90,21 fEv<W           CancelButton 190,91,90,21 HN~v&,           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 3A}nNHpN           TextBox 220,49,40,21,.TextBox2 'default: 4 ou,=MpXx*       End Dialog Jv4D^>yj[       Dim dlg As UserDialog #.<F5   !=h|&Vta       ok = Dialog (dlg) 9,EaN{GM   vACsppa>#       If ok=0 Then    'cancel button was pressed P9tQS"Rs           Print "Execution cancelled." u8k{N           End k,*#I<($       End If 5[j!\d}U   0Z);.l^       'Assign accommodation and pupil diameter & use defaults if field left empty %&=(,;d       If dlg.TextBox1 = "" Then mZ0oa-Iy           A = 0           'Default accommodation ;MRC~F=       Else pJ*#aH[ySP           A = CDbl(dlg.TextBox1) ("JV:u.L+       End If ^ yukn*L   sG1]A:_<C       If dlg.TextBox2 = "" Then D8D!16_           pupilDiam = 4   'Default pupil diameter Ignv|TYG       Else i\Q"a B"r           pupilDiam = CDbl(dlg.TextBox2) b#I*~       End If VgZaDd;   `d|bH;w       Print " " u0oYb_Yv       Print "Accommodation = " & A & " Diopters" )`+@j .75       Print "Pupil Diameter = " & pupilDiam & " mm" 8$ <AxNR   N7I71q|       ' Calculate new parameters with accommodation 7U[L\1zS       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness h3d\MYO)B   _l{5'm       Rant = 12.0 - 0.4*A                     'Radius of anterior lens K%TKQ<R|       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 2bn@:71`   UK<DcM~n       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens IL6f~!       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ^3)2]>pW   `7qp\vYL       tlens = 3.767 + 0.04*A                  'Lens thickness mv%:[+!   >5@vY?QXO       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction QH' [(   j.'"CU       'Adjust parameters to account for accommodation &<P^Tvqq&   Qdr-GODx       '************************************************************************* wAOVH].       'Aqueous thickness (Position of Lens) ~q T1<k       '************************************************************************* L|1zHDxQ       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Nb!6YY=Ez-       GetCustomElement eID, entity d,rEEc Y   O"^a.`27       parID = FindFullName( "Geometry.Arizona Eye" ) >'TD?@sr   L,A-G"z0Z       ' Delete any shift(s) in z Is6']bYh       count = 0 AB&wn>q       While GetOperationCount(eID)>count !4,xQ^            GetOperation eID, count, op ]vkHU6d           If op.Type="ShiftZ" Then )4_6\VaM               DeleteOperation eID,count A{Htpm~               count=count-1 '/Cz{<,           End If P"_}F           count=count+1 8!%"/*P$        Wend vgW1hWmHJ   (`y|AOs       'Set new shift in I.0P7eA-       op.Type = "ShiftZ" = 4WZr       op.val1 = taq Cbg#Yz~/       op.parent = parID I nK)O';       AddOperation eID, op cTaD{!zm5       Print "Set aqueous humor thickness = " & taq-0.55 /^eemx   c2mt<DtWW       '************************************************************************* cASHgm       'Radius and conic constant of anterior lens ftH%, /,       '************************************************************************* "sx&8H"       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ,Y8X"~{A       GetConic eID, entity, curv, conic :aqskeT   UR2)e{RXg       SetConic eID, entity, 1/Rant, CCant %e<dV\x?T       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant !K~$-jlT   ^r :A^q       '************************************************************************* ;GT)sI       'Radius and conic constant of posterior lens :QL p`s       '************************************************************************* RZh)0S>J       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) N_Ld,J%g       GetConic eID, entity, curv, conic [=F |^KL   G(\1{"!       SetConic eID, entity, 1/Rpost, CCpost ~[y+B0I3       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost }Q^a.`h   GFa/9Bi       '************************************************************************* \` ^Tbn:       'Lens thickness (Position of posterior lens surface) G5f57F       '************************************************************************* 'R'a/ZR`B7   Rs[] i;       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) l'%R^   $cU/Im`       ' Delete any z-shift(s) V(uRKu x       count = 0 jF_I4 H       While GetOperationCount(eID)>count YY~=h5$           GetOperation eID, count, op }z-           If op.Type="ShiftZ" Then PSR`8z n               DeleteOperation eID,count +M&S               count=count-1 oz-I/g3go           End If T5_Cu9>ax           count=count+1 N`6|Y       Wend !*UdY(   |6^ K       'Set new z-shift r$ Qh`[<       op.Type = "ShiftZ" PuCA @qY       op.val1 = tlens R>&/n/l       op.parent = parID 9G/2^PI       AddOperation eID, op wx5*!^&j       Print "Set lens thickness = " & tlens }3y\cv0ct   :]QxT8B       '************************************************************************* NWK_ (=n       'Lens index of refraction :?k=Yr       '************************************************************************* S Tk#hhx       eID = FindMaterial( "Lens" ) NYvj?>[y       GetModelMaterial eID, mat q:sR zX   fGWK&nONyk       mat.Nd = nlens Z@/5~p       SetModelMaterial eID, mat 2<@!m@       Print "Set lens index of refraction = " & nlens Y{tuaBzD   V<pjR@       '************************************************************************* kk+8NwM1       'Pupil diameter ITlkw~'G       '************************************************************************* S\!E;p       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) c (8J   j)qh>y)       'Adjust pupil diameter (trimming volume inner hole) <t37DnCgI   uwA3!5       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" *G41%uz   \hN2w]e       ' Adjust pupil location to just in front of the lens jpv,0(       parID = FindFullName( "Geometry.Arizona Eye" ) rNyK*Wjt       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) CHI(\DXNs       count = 0 0%+k>(@R       While GetOperationCount(eID)>count R,1,4X T           GetOperation eID, count, op hj,x~^cS           If op.Type="ShiftZ" Then eCd?.e0@j               DeleteOperation eID,count rtE, SN               count=count-1 I0RWdOK8K           End If dxWw%_Q           count=count+1 nTKfwIeg5       Wend ,$-PC=Ti(       op.Type = "ShiftZ" [F EQ@       op.val1 = taq-0.01 |Wk G='02       op.parent = parID hGV/P94       AddOperation eID, op +(%[fW   ;D:T ^4       Print "Set pupil diameter = " & pupilDiam qDAjW)w Jp   lZ_k307       'Update AZ Eye subassembly Description UI;{3Bn       eID = FindFullName( "Geometry.Arizona Eye" ) \/v$$1p2       GetEntity eID, entity [=+/       entity.Description = "Accommodation = " & A & "D" IhLfuyFWu       SetEntity eID, entity '%N)(S`O7P   d*L'`BBsp       Update CI{x/ e^(       Print "DONE!" yk 2j&}M        sN2l[Ous   End Sub {+Yo&F}n   h[T3WE   如果屈光度是4，光瞳直径是4，则会输出如下数据： VIzZmd   H #_Z6J   Accommodation = 4 Diopters ,-)1)R\.   Pupil Diameter = 4 mm mX^RSg9E}   Set aqueous humor thickness = 2.81 8t%1x|!   Set anterior lens radius = 10.4 and conic constant = -2.375869 B!@0(A   Set posterior lens radius = -4.424557 and conic constant = -3.081019 .~J^`/o   Set lens thickness = 3.927 _wCSL.   Set lens index of refraction = 1.42672 6bba}P   Set pupil diameter = 4 +F|[9o z   DONE!

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