Arizona眼睛模型

D}r,t_]Eb   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。 lrPiaSO`I   C2<!.l   模型 ^Bf@I   D4?5%s   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。 5^~%10=   Table 1. AZ眼睛模型的定义 KW]/u   a=+qR:wT   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. l} A8   a2 e-Q({   光源 GNlP]9wX   3i/$YX5@   多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 za`   |$`)d87,   图1. 光源和提示信息使用 iP6$;Y{ZA   a$y=+4L   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$]NQdz   T\55uQ   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 _@3@_GE   图2. 字母F光源的设定方法光 C: @T5m   CqDKQQ   图3. 字母F在视网膜上位置点列图 -{dsl|Dl   ~pWbD~aeg   视网膜的散射 p,.+i[V    m_LW<'   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 2>Bx/QF@<   HS =qK   图4. 视网膜朗伯散射设定 y w)q3zC   YKk? BQ"   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 2It$ bz   uDJi2,|n   图5. 视网膜重点采样规格设定 yJkERiJV   .{%~4$yu7   脚本 ^R',P(@oL   r<,W{Va   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： x2(!r3a   图6. 用户对话框的创建与编辑 !*_5 B'   图7. 用户对话框编辑器 5RCZv\Wd&   }>Gnpc   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。 AQ:cim`   余下的脚本计算与屈光度有关的所有参数。 zA4m !l*eM   ">PpC]Y1   分析 t2d_XQOK   i>#[*.|P   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 Ch8w_Jf1yx   图7. 字母F在视网膜上颜色分析 /*\pm!]._^   O*^=   脚本代码 )y&}c7xW   O&YX V   Option Explicit     'Remove this to enable non-dimensioned variables to be used. t>p!qKrE'J   *NzHY;e   Dim entity As T_ENTITY 1sKKmtgH   Dim op As T_OPERATION |y=;#A   Dim mat As T_MODELMATERIAL '#K:e   Dim A As Double R L&z\S   Dim pupilDiam As Double $K1 /^   Dim eID As Long ,b!!h]t   Dim parID As Long h$7rEs   Dim count As Integer ^{\gD23   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double JbN@AX:%   Dim tlens As Double, nlens As Double +rse,b&U(   Dim curv As Double, conic As Double cz<8Kb/XV   Dim ok As Long <>\s#Jf/   P[{qp8(g   Sub Main Gu} `X23    )f(.{M       '用户输入对话框 <8#Q5        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 DrE +{Spm           TextBox 220,21,40,21,.TextBox1 'default: 0 VbR/k,Co           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Esh3cn4           OKButton 40,91,90,21 O9y4.`a"           CancelButton 190,91,90,21 t}r`~AEa!           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 "J:~Aa% _           TextBox 220,49,40,21,.TextBox2 'default: 4 gx+bKGB`       End Dialog 0\3mS{s       Dim dlg As UserDialog $U=E7JO   0?kaXD       ok = Dialog (dlg) `;Qw/xl_N   |tL57Wu93       If ok=0 Then    'cancel button was pressed X :2% U           Print "Execution cancelled." $B6CLWB           End jM`)Nd       End If HsrIw   V/w:^@5+p       'Assign accommodation and pupil diameter & use defaults if field left empty Q|40 8EM       If dlg.TextBox1 = "" Then D4 {?f<G0F           A = 0           'Default accommodation R Fgy       Else aRFLh           A = CDbl(dlg.TextBox1) 01v7_*'R       End If C? pi8Xg   8vFt<k}G       If dlg.TextBox2 = "" Then yh9fHN)F           pupilDiam = 4   'Default pupil diameter ;{1J{- EA       Else cBICG",TA           pupilDiam = CDbl(dlg.TextBox2) 52+;j[ ]/O       End If jwsl"zL   WT(inf[       Print " " c)H(w       Print "Accommodation = " & A & " Diopters" a^yBtb~,P       Print "Pupil Diameter = " & pupilDiam & " mm" 08)X:@ w?   @\-i3EhR       ' Calculate new parameters with accommodation _isqk~ ul       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Nxk3uF^   RQ?T~ASs       Rant = 12.0 - 0.4*A                     'Radius of anterior lens 97"dOi!Wh       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens |n9~2R   VAkZ@ u3'~       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens DG_tmDT4       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens K:}~8 P>^   k2>gnk0       tlens = 3.767 + 0.04*A                  'Lens thickness Wtl0qug   e">$[IhXtV       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction \BB(0Ah+t   :uM2cc^       'Adjust parameters to account for accommodation B<.XowT'   ml7nt0{       '************************************************************************* 7%rSo^t,L       'Aqueous thickness (Position of Lens) _4E . P       '************************************************************************* EJqzh i5       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) f"XFf@!       GetCustomElement eID, entity k~|nU   _n9+ (X3       parID = FindFullName( "Geometry.Arizona Eye" ) >FtW~J"X   a }6Fj&hj       ' Delete any shift(s) in z }z/;^``       count = 0 HnvE\t9`       While GetOperationCount(eID)>count ciKkazx .           GetOperation eID, count, op cv fh:~L           If op.Type="ShiftZ" Then .E!p                DeleteOperation eID,count e@k`C{{C]o               count=count-1 ]:* 8 Mb#           End If (W~jr-O^           count=count+1 { "33 .^=       Wend x 'Z<   nJ/wtw       'Set new shift in )k5lA=(Yr+       op.Type = "ShiftZ" Sz0M8fYT]       op.val1 = taq /'|'3J]HP       op.parent = parID XQEGMaZ       AddOperation eID, op YJgw%UVJ5m       Print "Set aqueous humor thickness = " & taq-0.55 VdpkE0   T-7'#uB.m       '************************************************************************* @_0g "Ul       'Radius and conic constant of anterior lens 8kZ~       '************************************************************************* <j1l&H|ux,       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) '8~cf       GetConic eID, entity, curv, conic !O$*/7   eqbxf#H!       SetConic eID, entity, 1/Rant, CCant #8;|_RU       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant cvn4Q-^   +Ux)m4}j       '************************************************************************* ')#E,Y%Hq       'Radius and conic constant of posterior lens H[o'j@0       '************************************************************************* I`h9P2~       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) N"|^AF       GetConic eID, entity, curv, conic {]ZZ]   3j.Ft*SV       SetConic eID, entity, 1/Rpost, CCpost &fYx0JT       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost _I_Sq,Z#   cOUsbxYTD       '************************************************************************* 52B ye       'Lens thickness (Position of posterior lens surface) $Aww5G5e       '************************************************************************* *BVkviqxz   <[xxCW(2       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) /U<-N'|   LGT\1u       ' Delete any z-shift(s) GCrh4rxgg       count = 0 >HnD'y*       While GetOperationCount(eID)>count p}.P^`~j           GetOperation eID, count, op XF2u<sDe           If op.Type="ShiftZ" Then ]}9cOb%I               DeleteOperation eID,count ".| 9h               count=count-1 pTZPOv#?Q           End If JnCY O^Qj           count=count+1 zW%-Z6%D       Wend UuxWP\~2   P*/px4;6       'Set new z-shift NTiJEzW}       op.Type = "ShiftZ" \Ja%u"DA       op.val1 = tlens T4T_32`XR       op.parent = parID yY*OAC       AddOperation eID, op BZ1@?3       Print "Set lens thickness = " & tlens WX 79V   +8 [h&       '************************************************************************* J{$C}8V       'Lens index of refraction %Ua*}C        '************************************************************************* AEK* w4       eID = FindMaterial( "Lens" ) g=pz&cz;>\       GetModelMaterial eID, mat 7&NRE"?G   D>c%5h       mat.Nd = nlens ezlp~z"_k       SetModelMaterial eID, mat {i^ ?XdM       Print "Set lens index of refraction = " & nlens a#!Vi93   HeGGAjc       '************************************************************************* m&, d8Gss^       'Pupil diameter FHM^x2       '************************************************************************* ZERUvk       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 8nES=<rz   0"u*Kn       'Adjust pupil diameter (trimming volume inner hole) -J!F((jt   -N5r[*>       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" D8h?s   3w{4G<I       ' Adjust pupil location to just in front of the lens "rc}mq       parID = FindFullName( "Geometry.Arizona Eye" ) S~YrXQ{_>-       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 4,FkA_k       count = 0 e@k ti@ZJ       While GetOperationCount(eID)>count CJjma=XH           GetOperation eID, count, op \EYhAx`2           If op.Type="ShiftZ" Then FO3!tJ\L               DeleteOperation eID,count lhQ*;dMj%"               count=count-1 -K}@Gp           End If HJBUN1n           count=count+1 z2!NBOv       Wend S?hM       op.Type = "ShiftZ" aU4'_%Y@       op.val1 = taq-0.01 lDp5aT;DsM       op.parent = parID bvEk.~tC'       AddOperation eID, op !SiZA"   QwOQS %       Print "Set pupil diameter = " & pupilDiam %~Nf,   d^]wqnpf       'Update AZ Eye subassembly Description CNbrXN       eID = FindFullName( "Geometry.Arizona Eye" ) M%&`&{       GetEntity eID, entity ,X$S4>       entity.Description = "Accommodation = " & A & "D" 6gakopZO       SetEntity eID, entity zCO5`%14   3h0w8(k;       Update <%pi*:E|       Print "DONE!" ,dBtj8=        \jq1F9,   End Sub .h~)|"uzW   P|HY=RMa   如果屈光度是4，光瞳直径是4，则会输出如下数据： sS5#Q   ( }JX ]-   Accommodation = 4 Diopters !nuXK   Pupil Diameter = 4 mm f=/S]o4/3   Set aqueous humor thickness = 2.81 3w{i5gGn   Set anterior lens radius = 10.4 and conic constant = -2.375869 ?_<ZCH   Set posterior lens radius = -4.424557 and conic constant = -3.081019 /8W}o/,s5   Set lens thickness = 3.927 _?q\tyf3   Set lens index of refraction = 1.42672 webT   Set pupil diameter = 4 (CZRX9TT1   DONE!

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