Arizona眼睛模型

^.j Ius5   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。 )ARfI)<1b   C$ cX{hV   模型 Fs_V3i3|L   VkFTIyt   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。 &O5%6Sv3d   Table 1. AZ眼睛模型的定义 7~TE=t   l epR}   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. f5zxy!dhKS   +#O?a`f   光源 cX"[#Em#   HB`u@9le   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。 F>&Q5Kl R   5~4I.+~8   图1. 光源和提示信息使用 Z 2Fm=88   X<ZIeZBn   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。 Y[Us"K`   <QTu"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。 a^i`DrX   图2. 字母F光源的设定方法光 YMLo~j4J   0wXfu"E{   图3. 字母F在视网膜上位置点列图 F7UY>z3jL   Hk8:7"4Q   视网膜的散射 bmna*!l^M   T=:&W3   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。 x_{ua0BLDf   *ghkw9/   图4. 视网膜朗伯散射设定 -cNh5~p=   #wbaRx@rc   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。 vG#|CO9   wlBdA   图5. 视网膜重点采样规格设定 ~;#J&V@D   z~+_sTu   脚本 QsI#Ae,O#;   EaFd1   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： 6'395x_.\   图6. 用户对话框的创建与编辑 -vwkvNn8   图7. 用户对话框编辑器 <M=U @   No<2+E!   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。 )mxY]W+   余下的脚本计算与屈光度有关的所有参数。 |gx{un`   L7_Mg{   分析 vlIet$k   3SVI|A5(d   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 %m!o#y(hD`   图7. 字母F在视网膜上颜色分析 6tI7vLmG    >>Hsx2M   脚本代码 9c8zH{T_{   =#n05*^   Option Explicit     'Remove this to enable non-dimensioned variables to be used. C\dQ6(3}\   8^&)A b   Dim entity As T_ENTITY IV;juFw}G   Dim op As T_OPERATION !(F+~,   Dim mat As T_MODELMATERIAL lZV]Z3=p'0   Dim A As Double 2GXAq~h@   Dim pupilDiam As Double [nn/a?Z4S   Dim eID As Long AvRZf-Geg   Dim parID As Long BqP:]   Dim count As Integer jpZX5_o   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double aoz+g,1 //   Dim tlens As Double, nlens As Double ;gy_Qf2U   Dim curv As Double, conic As Double kf_s.Dedw   Dim ok As Long \% !]qv   f'TjR#w   Sub Main 03J,NXs   qD7(+ a       '用户输入对话框 f'\I52;FB       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 }fZT$'*;           TextBox 220,21,40,21,.TextBox1 'default: 0 a2vUZhkR           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 oiJa1X           OKButton 40,91,90,21 5|NM]8^^0[           CancelButton 190,91,90,21 6#7f^uIK           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 C"k8M\RW?           TextBox 220,49,40,21,.TextBox2 'default: 4 Dd<gYPC       End Dialog -WE pBt7*       Dim dlg As UserDialog m/=,O_   ss T o?WL|       ok = Dialog (dlg) [ hm/B`t*e   x^8xz5:O       If ok=0 Then    'cancel button was pressed y1cAw            Print "Execution cancelled." wWY6DQQB           End e%`gD*8       End If _D1bR7   g?A4C`l6iy       'Assign accommodation and pupil diameter & use defaults if field left empty o B_c6]K       If dlg.TextBox1 = "" Then "'94E,W           A = 0           'Default accommodation mV@.JFXKP       Else -5>K pgXo\           A = CDbl(dlg.TextBox1) JMuUj_^}7       End If FlOKTY   gEIjG       If dlg.TextBox2 = "" Then (-(,~E           pupilDiam = 4   'Default pupil diameter ggVB8QN{       Else -9}]J\           pupilDiam = CDbl(dlg.TextBox2) ^>h 9<       End If z[0L?~$   "^;'.~@e8       Print " "  }/x `w       Print "Accommodation = " & A & " Diopters" FfI$3:9       Print "Pupil Diameter = " & pupilDiam & " mm" QKCc5   Ik>sd@X*|       ' Calculate new parameters with accommodation Kqce lI?-I       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness SLSJn))@!   .MhZ=sn       Rant = 12.0 - 0.4*A                     'Radius of anterior lens ,aV89"}       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens \s`'3y   F:n(y XA       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens <po.:c Ce       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Pw1V1v&>q   92]>"       tlens = 3.767 + 0.04*A                  'Lens thickness yi"V'Us   .r[DqC       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 4fr/ C5M   NAZxM9       'Adjust parameters to account for accommodation VeA;zq   [`=|^2n?       '************************************************************************* WfhQi;r       'Aqueous thickness (Position of Lens) `8xmMA_l       '************************************************************************* {ogGi/8       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) >sm< < gVb       GetCustomElement eID, entity `R!0uRu   {}D8Y_=9\       parID = FindFullName( "Geometry.Arizona Eye" ) Fb*^GH)J   )$P!7$C-       ' Delete any shift(s) in z 58mzh 82+       count = 0 j()_ VoB1       While GetOperationCount(eID)>count }LM^>M%           GetOperation eID, count, op |ZJ]`qmZ           If op.Type="ShiftZ" Then ~uqJ@#o{               DeleteOperation eID,count W6K]jIQ               count=count-1 Rr^<Q:#"<|           End If  M)Yu^           count=count+1 wS%I.       Wend x(hUQu 6   2xni! *T+       'Set new shift in ?%JH4I2       op.Type = "ShiftZ" s_.q/D@vu       op.val1 = taq r*>XkM& M       op.parent = parID U2ecvq[T       AddOperation eID, op uCNQ.Nbf C       Print "Set aqueous humor thickness = " & taq-0.55 CmJI"    %HL@O]ftS       '************************************************************************* Pgr>qcbql       'Radius and conic constant of anterior lens H[*.Jd       '************************************************************************* 'ujtw:Z:       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) :?RooJ~#       GetConic eID, entity, curv, conic &Km?(%?   PP[{c       SetConic eID, entity, 1/Rant, CCant #|A @       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant HMgZ& v    3iV/7~ O       '************************************************************************* 1#(,Bq4       'Radius and conic constant of posterior lens YXg:cXE8e       '************************************************************************* .<u<!fL2       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) =k2+VI       GetConic eID, entity, curv, conic [uc;M6o}?   b-M[la}1"       SetConic eID, entity, 1/Rpost, CCpost {u9(qd;;       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost X~P0Q   A}~hc&J       '************************************************************************* T_[W=9       'Lens thickness (Position of posterior lens surface) yIXM}i:       '************************************************************************* Mq[;:   =XQ3sk6U       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) wx}\0(]Gl   , j'=sDl       ' Delete any z-shift(s) HpDU:m       count = 0 H3QAIsGS       While GetOperationCount(eID)>count @K4} cP           GetOperation eID, count, op MZn7gT0           If op.Type="ShiftZ" Then qnrf%rS               DeleteOperation eID,count _<pG}fmR               count=count-1 }C2I9Cl           End If > :!faWX           count=count+1 WB6g i2       Wend x2Y1B   }!Qo wG       'Set new z-shift /B|#GJ\\3       op.Type = "ShiftZ" un W{ZfEC       op.val1 = tlens  O7s0M?4       op.parent = parID oxPOfI1%]       AddOperation eID, op bk2HAG       Print "Set lens thickness = " & tlens ]AERi] B   Z)P x6\?+       '************************************************************************* Yah3I@xGy       'Lens index of refraction A{x&5yX8       '************************************************************************* o%M~Q<wf       eID = FindMaterial( "Lens" ) 7R7g$       GetModelMaterial eID, mat =ub&@~E   KOhy)h+ h       mat.Nd = nlens -CtA\<7I       SetModelMaterial eID, mat P:(,l,}F8       Print "Set lens index of refraction = " & nlens S,G=MI"   U+@yx>!       '************************************************************************* Mr2dhSQ!       'Pupil diameter e>nRJH8pK       '************************************************************************* Ip.5I!h[Xb       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) L.U [eH   @ewQx|       'Adjust pupil diameter (trimming volume inner hole) FLEf(   Bwb3@vNA       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" (G#)[0<fX   e<~uU9 lg1       ' Adjust pupil location to just in front of the lens 4)JrOe&k       parID = FindFullName( "Geometry.Arizona Eye" ) 4{CVBowi       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) .}SW`RPk       count = 0 wXuHD<<       While GetOperationCount(eID)>count =<`9T_S 16           GetOperation eID, count, op %?X~,           If op.Type="ShiftZ" Then E|6X.Ny]                DeleteOperation eID,count Va(R*38k               count=count-1 F 3H)B:           End If VG2TiR1           count=count+1 N(t1?R/e ,       Wend 3t68cdFlz       op.Type = "ShiftZ" "4`h -Y       op.val1 = taq-0.01 4K0N$9pd:       op.parent = parID R/ l1$}       AddOperation eID, op 3z\:{yl   Z7k {7       Print "Set pupil diameter = " & pupilDiam w^G<]S{l   U>:CX XHRt       'Update AZ Eye subassembly Description qZKU=HM       eID = FindFullName( "Geometry.Arizona Eye" ) +s1+;VUs3       GetEntity eID, entity jTSw0\}       entity.Description = "Accommodation = " & A & "D" j\@s pbE@       SetEntity eID, entity o2a`4K   [ {lF1+];@       Update qIA!m .GC       Print "DONE!" $w+g%y)        [FF%HRce,.   End Sub bC?t4-W   {Swou>X4   如果屈光度是4，光瞳直径是4，则会输出如下数据： T=;'"S   >^n'   Accommodation = 4 Diopters C*kZ>mbc   Pupil Diameter = 4 mm _P,fJ`w   Set aqueous humor thickness = 2.81 H'?Bx>X   Set anterior lens radius = 10.4 and conic constant = -2.375869  EvTdwX.H   Set posterior lens radius = -4.424557 and conic constant = -3.081019 r{>tTJFD(:   Set lens thickness = 3.927 s67$tlV   Set lens index of refraction = 1.42672 .LnXKRd{   Set pupil diameter = 4 qZ`@Ro   DONE!

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