[分享]Arizona眼睛模型 [复制链接]

简介 SbZt\a 8  
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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。 d|]O<]CG_  
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模型 N;'HR)  
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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。 Y/H^*1  
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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. P]"deB|  
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光源 d&uTiH?0  
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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。 ^,lZ58 2  
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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。 1~DD9z  
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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。 *Ca)RgM  
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视网膜的散射 <{420  
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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。 tRnW%F5  
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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。 ?
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脚本 _/}Hqh  
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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_<s=nTX  
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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。
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余下的脚本计算与屈光度有关的所有参数。 xs'kO=  
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分析 nS+FX&_  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 /.)[9bQ<  
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脚本代码 tB7K&ssi  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. )p<fL  
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Dim entity As T_ENTITY px|>
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Dim op As T_OPERATION !ml_S)  
Dim mat As T_MODELMATERIAL
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Dim A As Double Nxb\[  
Dim pupilDiam As Double px_s@>l`  
Dim eID As Long W&e'3gk_  
Dim parID As Long z0 2}&^Zzk  
Dim count As Integer 4e@&QOo`Cu  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double .vN%UNu  
Dim tlens As Double, nlens As Double 6!+X.+  
Dim curv As Double, conic As Double [Iw>|q<e  
Dim ok As Long @1v3-n=  
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Sub Main 0AK?{y U  
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    '用户输入对话框 1Sg|3T8bGT  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 N )zPxQ  
        TextBox 220,21,40,21,.TextBox1 'default: 0 v._Egk0  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 K[uY+!'1  
        OKButton 40,91,90,21 gT(th9'+z  
        CancelButton 190,91,90,21 -J"qrp
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 "Su b4F`  
        TextBox 220,49,40,21,.TextBox2 'default: 4 &_9YLXtMi;  
    End Dialog t/KcXM  
    Dim dlg As UserDialog -c+>j  
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    ok = Dialog (dlg) <rX\LwR  
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    If ok=0 Then    'cancel button was pressed =
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        Print "Execution cancelled." nTys4R  
        End P>*Fj4Z~  
    End If ]By0Xifew  
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    'Assign accommodation and pupil diameter & use defaults if field left empty *wC\w  
    If dlg.TextBox1 = "" Then =U4f}W;  
        A = 0           'Default accommodation /Jxq 3D)v  
    Else onnI !  
        A = CDbl(dlg.TextBox1) @[MO,J&h  
    End If *.,"N}  
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    If dlg.TextBox2 = "" Then 7hB#x]oQo  
        pupilDiam = 4   'Default pupil diameter j)jCu ;`  
    Else |7 &|>  
        pupilDiam = CDbl(dlg.TextBox2) #^|| ]g/N  
    End If Mv
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    Print " " CifA,[l34  
    Print "Accommodation = " & A & " Diopters" 2E^"r jLm  
    Print "Pupil Diameter = " & pupilDiam & " mm" fL!V$]HNt  

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    ' Calculate new parameters with accommodation zlH28V  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness tNK^z7Dm  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ~Fy`>*  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ~?#~Ar  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens tY/En-&t  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens w{PUj  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Bk,2WtVX  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction jcE Msc  
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    'Adjust parameters to account for accommodation SOVjEo4'3  
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    '*************************************************************************
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    'Aqueous thickness (Position of Lens) YWEYHr;%^?  
    '************************************************************************* H#OYw#L"u  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) J*5hf:?i  
    GetCustomElement eID, entity a$d:_,\"  
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    parID = FindFullName( "Geometry.Arizona Eye" ) j(j#0dXLh  
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    ' Delete any shift(s) in z jh[ #p?:  
    count = 0 -$.0Dc)3!  
    While GetOperationCount(eID)>count TN5>"??"  
        GetOperation eID, count, op Hb+
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        If op.Type="ShiftZ" Then u t$c)_  
            DeleteOperation eID,count e,(a6X  
            count=count-1 ymYBm:"  
        End If @Tm`d ?^  
        count=count+1 _6ZzuVv3/  
    Wend jgG$'|s}  
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    'Set new shift in 7'z(~3D  
    op.Type = "ShiftZ" E, GN|l  
    op.val1 = taq ?ty>}.c t  
    op.parent = parID P$_&  
    AddOperation eID, op ~(P&g7u  
    Print "Set aqueous humor thickness = " & taq-0.55 LT/mb2  
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    '************************************************************************* {Ur7#h5  
    'Radius and conic constant of anterior lens 6hO-H&r++  
    '************************************************************************* xYPxg!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) :5J_5,?;`
 
    GetConic eID, entity, curv, conic eIH$"f;L  
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    SetConic eID, entity, 1/Rant, CCant $E\^v^LW  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 802H$P^ps  
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    '************************************************************************* L_~8"I_  
    'Radius and conic constant of posterior lens M diwRi  
    '************************************************************************* 5X#E@3g5  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) -jB3L:  
    GetConic eID, entity, curv, conic ^*0'\/N&  
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    SetConic eID, entity, 1/Rpost, CCpost @ &pqt6/t  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost BgM%+b8u  
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    '************************************************************************* H]&gW/=  
    'Lens thickness (Position of posterior lens surface) zyFUl%  
    '************************************************************************* y\D=Z N@  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ?{6s58Q{  
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    ' Delete any z-shift(s) 5!(?m~jJ  
    count = 0 Wpr ,jN8b  
    While GetOperationCount(eID)>count d$G}iJ8$mp  
        GetOperation eID, count, op ?2 f_aY ;  
        If op.Type="ShiftZ" Then 0J9D"3T)  
            DeleteOperation eID,count T7[NcZ:I  
            count=count-1 bWmw3w  
        End If #$E)b:xj  
        count=count+1 2:SO_O4C  
    Wend
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    'Set new z-shift l$XPIC~H  
    op.Type = "ShiftZ" [%pRfjM  
    op.val1 = tlens ,6{iT,~@8  
    op.parent = parID <CZgQ\Mt  
    AddOperation eID, op sILSey5`  
    Print "Set lens thickness = " & tlens __Nv0Ru  
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    '************************************************************************* p*20-!{A  
    'Lens index of refraction j.%K_h?V5  
    '************************************************************************* %%JMb=!%2  
    eID = FindMaterial( "Lens" ) xr%#dVk  
    GetModelMaterial eID, mat n}?wVfEy  
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    mat.Nd = nlens G8J*Wnwu[K  
    SetModelMaterial eID, mat Pw[g  
    Print "Set lens index of refraction = " & nlens Nd@~>&F  
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    '************************************************************************* oM1Qh?  
    'Pupil diameter NxA)@9Q  
    '************************************************************************* Iz@)!3h  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) mJ}opy!{;  
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    'Adjust pupil diameter (trimming volume inner hole) VIJ<``9[  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" [p;E~-S  
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    ' Adjust pupil location to just in front of the lens SF[FmN!^^  
    parID = FindFullName( "Geometry.Arizona Eye" ) )]htm&q5  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) n, i'Dhzk  
    count = 0 .@F]Pht  
    While GetOperationCount(eID)>count 3W_PE+:Kr  
        GetOperation eID, count, op Qf$|_&|  
        If op.Type="ShiftZ" Then &--ej|n  
            DeleteOperation eID,count -
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            count=count-1 Y>+y(ck  
        End If jMNU ?m:  
        count=count+1 DA&?e~L&H  
    Wend XB59Vm0E=  
    op.Type = "ShiftZ" w= P9FxB  
    op.val1 = taq-0.01 "vZ!vt#'Y  
    op.parent = parID $~;D9  
    AddOperation eID, op *%/~mSx  
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    Print "Set pupil diameter = " & pupilDiam \QE)m<G
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    'Update AZ Eye subassembly Description 26vp1  
    eID = FindFullName( "Geometry.Arizona Eye" ) .iX# A<E}  
    GetEntity eID, entity }a AH  
    entity.Description = "Accommodation = " & A & "D" d5 7i)=  
    SetEntity eID, entity A][fLlpr  
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    Update MY#   
    Print "DONE!" $-}e; VZb  
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End Sub b` Hz$8  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： l>*"mh  
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Accommodation = 4 Diopters kHw_ S-  
Pupil Diameter = 4 mm
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Set aqueous humor thickness = 2.81 'R`tLN  
Set anterior lens radius = 10.4 and conic constant = -2.375869 w@JKl5  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 4lhw3,5  
Set lens thickness = 3.927 evkH05+;W  
Set lens index of refraction = 1.42672 M])dJ9&e  
Set pupil diameter = 4 )9l^O  
DONE! 6`vC1PK^  
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