Arizona眼睛模型

!;}2F -   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。 #3.)H9   P1d,8~;   模型 U}P,EP%p   _-a|VTM   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。 r\mPIr|   Table 1. AZ眼睛模型的定义 23E0~O   W8/(;K`/   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. co]Gmg6p   ^87 42.   光源 Xem| o&   zO2{.4   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。 U)~#g'6:8   Qb@eK$wo}   图1. 光源和提示信息使用 3q~Fl=|. o   {[3YJkrM   除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 q) _r3    iSd?N}2,I   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 UH40~LxIma   图2. 字母F光源的设定方法光 0eA5zFU7   syFI$rf _   图3. 字母F在视网膜上位置点列图 ZlM_m >,o   F$ {4X /9n   视网膜的散射 G2@KI-   R~c1)[[E   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。 qc-C>Ra   n0FYfqH   图4. 视网膜朗伯散射设定 #<}kISV0   ]PVto\B=   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。 q]ZSjJ   bA+[{   图5. 视网膜重点采样规格设定 $B ?? Ip?P   3Q$c'C   脚本 NEg>lIu<~   x vJ^@w'   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： Qi|?d7k0   图6. 用户对话框的创建与编辑 y*|L:!    图7. 用户对话框编辑器 \)GR\~z0h   )8]3kQffJ=   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。 dqwWfn1lt   余下的脚本计算与屈光度有关的所有参数。 [iXi\Ex   3se$,QmN   分析 ~bFdJj 1*   4]u,x`6C   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 7uA\&/ ,   图7. 字母F在视网膜上颜色分析 uf?b%:A   .r*#OUC   脚本代码 a'^0.1   #}j]XWy   Option Explicit     'Remove this to enable non-dimensioned variables to be used. X=#It&m%s   P09,P    Dim entity As T_ENTITY f:FpyCo=9   Dim op As T_OPERATION G)4SWu0<t   Dim mat As T_MODELMATERIAL ytob/tc   Dim A As Double F b2p(.   Dim pupilDiam As Double 1::LN(`<   Dim eID As Long VB's   Dim parID As Long i)8gCDc   Dim count As Integer A{t"M-<   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double V:QdQ;c   Dim tlens As Double, nlens As Double W\a!Q]pV   Dim curv As Double, conic As Double 79a9L{gso   Dim ok As Long g X8**g'   vQcUaPm\$   Sub Main l)%mqW%   lnjL7x       '用户输入对话框 uYY=~o[ Tw       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 pbFYiu+           TextBox 220,21,40,21,.TextBox1 'default: 0 8eN%sm           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 7NeDs$           OKButton 40,91,90,21 dGa@<hg           CancelButton 190,91,90,21 -@#Pc#           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 oN4G1U Kc           TextBox 220,49,40,21,.TextBox2 'default: 4 bbO+%-(X       End Dialog  +!G4tA$g       Dim dlg As UserDialog D|"sE>   s?5d       ok = Dialog (dlg) {DSyV:   qZ233pc       If ok=0 Then    'cancel button was pressed 22PGWSQ           Print "Execution cancelled." OoE9W           End MHGjvSx       End If s5nB(L*Pjp   {GAsFnZk       'Assign accommodation and pupil diameter & use defaults if field left empty ?${V{=)*X'       If dlg.TextBox1 = "" Then 4YBf ~Pp           A = 0           'Default accommodation ZHb7+       Else '}@e5^oL           A = CDbl(dlg.TextBox1) jm4)gmC       End If ^z38<L=z"   /%-o.hT       If dlg.TextBox2 = "" Then ;r%<2 (           pupilDiam = 4   'Default pupil diameter n}+wd9J*!2       Else }Z^FEd"y           pupilDiam = CDbl(dlg.TextBox2) _ \_3s       End If :l4^iSf   gZ1N&/9;       Print " " #&}%70R)       Print "Accommodation = " & A & " Diopters" gYRq qV       Print "Pupil Diameter = " & pupilDiam & " mm" =z+-l5Gu"   )_X;9%L7       ' Calculate new parameters with accommodation vY4WQbz(       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness #j\*Lc"Ur:   %f_FGh       Rant = 12.0 - 0.4*A                     'Radius of anterior lens ]~$c~*0g       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 3&O% &   eB)UXOu1       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens q$bHO       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens (H'_KPK   b?sAEU;       tlens = 3.767 + 0.04*A                  'Lens thickness o-L|"3P   lkI8{       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction -Mr{+pf   X*_ SHt       'Adjust parameters to account for accommodation hgF21Oj9   jn0t-":       '************************************************************************* TXA. 6e       'Aqueous thickness (Position of Lens) ^H f+du       '************************************************************************* 1!K!oY       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) z?8zFP       GetCustomElement eID, entity W ]a7&S   e{c._zr,       parID = FindFullName( "Geometry.Arizona Eye" ) n P0Ziu'{   jI@bTS o       ' Delete any shift(s) in z %Y#[%~|(       count = 0 >^M!@=/?J       While GetOperationCount(eID)>count MBnK&GS           GetOperation eID, count, op |:!EHFr           If op.Type="ShiftZ" Then <|mE9u               DeleteOperation eID,count oVKsic?               count=count-1 3(oZZz           End If ZE5-i@1           count=count+1 CUAg{]       Wend K8e4ax   @h,h=X       'Set new shift in \9&YV;Ct       op.Type = "ShiftZ" yt]Oj*nn0K       op.val1 = taq r*~n`       op.parent = parID (ouRf;\6$8       AddOperation eID, op mtiO7w"M\7       Print "Set aqueous humor thickness = " & taq-0.55 dVY(V&p   X3&SL~&>g       '************************************************************************* hlABu)B'1       'Radius and conic constant of anterior lens Z&?+&q r^       '************************************************************************* f(@"[-[       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) G}Qk!r       GetConic eID, entity, curv, conic uIVTs9\   +35)=Uov       SetConic eID, entity, 1/Rant, CCant b |o`Q7Hj       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant -(%ar%~Zd   ifgr<QlG       '************************************************************************* 6Zl.Lh       'Radius and conic constant of posterior lens USHlb#*       '************************************************************************* YUP%K!k       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) {="Su{i}}       GetConic eID, entity, curv, conic ;r0|_mnf   A*-]J=:E {       SetConic eID, entity, 1/Rpost, CCpost rU2YMghE       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost !#_h2a   0C"PC:h5       '************************************************************************* l&e5_]+%       'Lens thickness (Position of posterior lens surface) $)kBz*C[       '************************************************************************* HL}sqcp   ?-RoqF       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) X*c_^g{   *'AS^2'       ' Delete any z-shift(s) yP1Y3Tga=       count = 0 {m*V/tX       While GetOperationCount(eID)>count +*r**(-Dm           GetOperation eID, count, op )$Dcrrj           If op.Type="ShiftZ" Then pJ)+}vascR               DeleteOperation eID,count yccuTQvz               count=count-1 mV! @oNCK           End If K@$L~G           count=count+1 #sm_.?P       Wend 67KRM(S   + 8K1]'t$       'Set new z-shift fW4cHB9|       op.Type = "ShiftZ" _L `N^I.       op.val1 = tlens ?( dYW7S       op.parent = parID 3Q!J9t5dc       AddOperation eID, op n'&`9M['%d       Print "Set lens thickness = " & tlens +{=_|3(   7S~9E2N       '************************************************************************* ou,=MpXx*       'Lens index of refraction Jv4D^>yj[       '************************************************************************* #.<F5       eID = FindMaterial( "Lens" ) r PRuSk-f       GetModelMaterial eID, mat !>Qc2&ZV   5qtmb4R~       mat.Nd = nlens 8t*%q+Z       SetModelMaterial eID, mat _c(C;s3o       Print "Set lens index of refraction = " & nlens E23 Yk?"   Rm\'];       '************************************************************************* UmD-7Fd       'Pupil diameter "<jEI /       '************************************************************************* ,;=( )-       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 8HRPJSO~g   :C:N]6_{SZ       'Adjust pupil diameter (trimming volume inner hole) ^]lwd"$   "aCb;2Rs       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" KZ< RDXVT   j~L1~@       ' Adjust pupil location to just in front of the lens s eZ<52f2       parID = FindFullName( "Geometry.Arizona Eye" ) mTuB *       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) b#I*~       count = 0 VgZaDd;       While GetOperationCount(eID)>count b-(UsY:           GetOperation eID, count, op o"ah\"#el           If op.Type="ShiftZ" Then g <T`F               DeleteOperation eID,count 1-NX>E5               count=count-1 MkNURy> n&           End If HT,kx           count=count+1 iZq@W3GL C       Wend rX>y>{w~       op.Type = "ShiftZ" 72`/xryY       op.val1 = taq-0.01 -IEP?NX       op.parent = parID ">vYEkZ3       AddOperation eID, op L5k>;|SA   0iZ9a/v       Print "Set pupil diameter = " & pupilDiam T;[c<gc/   e9_O/iN       'Update AZ Eye subassembly Description lKhh=Pc2       eID = FindFullName( "Geometry.Arizona Eye" ) QH' [(       GetEntity eID, entity 6[h$r/GXh"       entity.Description = "Accommodation = " & A & "D" &<P^Tvqq&       SetEntity eID, entity Qdr-GODx   J_[[BJ&}x       Update 5f*' wA       Print "DONE!" ,S0~:c:)        b`W'M:$   End Sub ExP25T   UrcN?   如果屈光度是4，光瞳直径是4，则会输出如下数据： 'GzhZ `E6   7fTg97eF   Accommodation = 4 Diopters ,f0g|5yDf   Pupil Diameter = 4 mm qD%&\ZT   Set aqueous humor thickness = 2.81 $E,DxDT   Set anterior lens radius = 10.4 and conic constant = -2.375869 ;1g-z]   Set posterior lens radius = -4.424557 and conic constant = -3.081019 0G\ myv   Set lens thickness = 3.927 w$;*~Qc   Set lens index of refraction = 1.42672 Y7V&zF{   Set pupil diameter = 4 Y$$?8xr ~   DONE!

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