[分享]Arizona眼睛模型 [复制链接]

简介 lJ/6-dP  
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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。 r#h {$i
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模型 b :\D\X  
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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。 OhWC}s  
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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. 7>je6*(K  
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光源 h%b
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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。 z[#6-T &  
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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。 EVz9WY  
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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。 -uR{X G. D  
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视网膜的散射 &q>h*w4O  
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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。 XARSGAuw  
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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。 (-2R{!A  
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脚本 bw;iz,Z  
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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： onh?/3l  
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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。 Nh :JU?h  
余下的脚本计算与屈光度有关的所有参数。 +9~ZA3DiP  
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分析 uXP- J]>  
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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。 bXm:]?  
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脚本代码 xOgq-@`  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ?:JdRnH\  
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Dim entity As T_ENTITY 0O^r.&{j>  
Dim op As T_OPERATION !xJFr6G~8  
Dim mat As T_MODELMATERIAL
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Dim A As Double ndB@J*Im
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Dim pupilDiam As Double Lqq*Nr  
Dim eID As Long -YAO3  
Dim parID As Long %N1T{   
Dim count As Integer l]/> `62  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double W
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Dim tlens As Double, nlens As Double i63?"  
Dim curv As Double, conic As Double IwnYJp:9v  
Dim ok As Long &LwJ'h+nd  
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Sub Main =^"~$[
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    '用户输入对话框 h#;?9DP  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 >Ziy1Dp  
        TextBox 220,21,40,21,.TextBox1 'default: 0 )*+u\x_Hx  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 =cknE=  
        OKButton 40,91,90,21 mnQal>0~  
        CancelButton 190,91,90,21 ?
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 '|J)ds  
        TextBox 220,49,40,21,.TextBox2 'default: 4 7kO
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    End Dialog #Xj;f^}/  
    Dim dlg As UserDialog y K=S!7p\  
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    ok = Dialog (dlg) EOofa6f&l  
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    If ok=0 Then    'cancel button was pressed :R{x]sv  
        Print "Execution cancelled." es{cn=\s  
        End 55(J&q  
    End If ]kzv8#  
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    'Assign accommodation and pupil diameter & use defaults if field left empty VoWA
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    If dlg.TextBox1 = "" Then *c!;^Qyp&  
        A = 0           'Default accommodation 4;",@}  
    Else ZKZl>dDuh  
        A = CDbl(dlg.TextBox1) ;sm"\.jF  
    End If b"`ru~]  
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    If dlg.TextBox2 = "" Then t@l(xnsV  
        pupilDiam = 4   'Default pupil diameter Cca~Cq[%*(  
    Else Ax :3}  
        pupilDiam = CDbl(dlg.TextBox2) 5~v(AB(x  
    End If rDK;6H:u{  
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    Print " " (9Fabo\SH  
    Print "Accommodation = " & A & " Diopters" L?AM&w-cg9  
    Print "Pupil Diameter = " & pupilDiam & " mm" aslU`#"  
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    ' Calculate new parameters with accommodation Fc34Y0_A  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness LuQ"E4;nY%  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens uEc0/a :.  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens /8 e2dw: \  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens V=G b>_d  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens fho=<|-  
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    tlens = 3.767 + 0.04*A                  'Lens thickness !C9ps]6
 
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction z }FiU
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    'Adjust parameters to account for accommodation qAS70XjOF  
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    '************************************************************************* ] P:NnKgK  
    'Aqueous thickness (Position of Lens) 8MYLXW6  
    '************************************************************************* ^&f{beU9  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) P5yJO9
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    GetCustomElement eID, entity f}Ne8]U/Hc  
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    parID = FindFullName( "Geometry.Arizona Eye" ) c,3'wnui  
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    ' Delete any shift(s) in z ]%cHm4#m3  
    count = 0 Fi?U)T+%+  
    While GetOperationCount(eID)>count sw3:HNG=  
        GetOperation eID, count, op M~d+HE  
        If op.Type="ShiftZ" Then A{DIp+  
            DeleteOperation eID,count Z`SWZ<  
            count=count-1 Fy4<  
        End If t z +  
        count=count+1 w /Bn2bD  
    Wend 2|T|K?R^  
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    'Set new shift in )V9Mcr*Ce6  
    op.Type = "ShiftZ" :Ul'(@  
    op.val1 = taq >q} !>k$B  
    op.parent = parID !4qp
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    AddOperation eID, op s/W!6JX4  
    Print "Set aqueous humor thickness = " & taq-0.55 !%Z)eO~Z  
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    '************************************************************************* onWYT}c{  
    'Radius and conic constant of anterior lens LP0;n\  
    '************************************************************************* M[`w{A  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 6\)8mK  
    GetConic eID, entity, curv, conic lzr>WbM{{p  
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    SetConic eID, entity, 1/Rant, CCant )$9C`d[  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant U 3wsWSO  
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    '************************************************************************* HiS,q0  
    'Radius and conic constant of posterior lens 8a":[Q[  
    '************************************************************************* :e0R7sj  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Yq)YS]  
    GetConic eID, entity, curv, conic `/gEKrhL-  
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    SetConic eID, entity, 1/Rpost, CCpost ?}1JL6mF{  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost YP .%CD(K  
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    '************************************************************************* mhJOR'2  
    'Lens thickness (Position of posterior lens surface) "I}'C^gP  
    '************************************************************************* =@ 
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Qn'r+X5t  
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    ' Delete any z-shift(s) x
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    count = 0 9`gGsC  
    While GetOperationCount(eID)>count 0%&fUz36E6  
        GetOperation eID, count, op %xbz&'W,  
        If op.Type="ShiftZ" Then S7#^u`'Q_^  
            DeleteOperation eID,count
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            count=count-1 a dz;N;rIY  
        End If ?O.6r"  
        count=count+1 A Eyr_!G,  
    Wend nkCRe  
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    'Set new z-shift YiI:uG!|D  
    op.Type = "ShiftZ" [pC-{~  
    op.val1 = tlens (8m\#[T+R  
    op.parent = parID jQK2<-HZ3  
    AddOperation eID, op aP6%OI  
    Print "Set lens thickness = " & tlens *C:q _/  
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    '*************************************************************************
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    'Lens index of refraction 3bbp>7V!  
    '************************************************************************* NCowt|#t  
    eID = FindMaterial( "Lens" ) 3W7;f!  
    GetModelMaterial eID, mat Kcs
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    mat.Nd = nlens ~_DF06G  
    SetModelMaterial eID, mat 1A7%0/K-]  
    Print "Set lens index of refraction = " & nlens G$?|S@I,  
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    '************************************************************************* ^%\)Xi  
    'Pupil diameter 
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    '************************************************************************* <^,o$b  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) U}tl_5%)  
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    'Adjust pupil diameter (trimming volume inner hole) kZV^F*7  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" A[u)wX^`f^  
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    ' Adjust pupil location to just in front of the lens Zu\p;!e  
    parID = FindFullName( "Geometry.Arizona Eye" ) ksB  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ]]el|  
    count = 0 1a7!4)\  
    While GetOperationCount(eID)>count mgi,b2  
        GetOperation eID, count, op iBG`43;  
        If op.Type="ShiftZ" Then 5h_<R!jA  
            DeleteOperation eID,count <lC]>
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            count=count-1 "KMLk  
        End If 6eOrs-ty  
        count=count+1 cU7rq j_  
    Wend Hze-Ob8  
    op.Type = "ShiftZ" Z} c'Bm(  
    op.val1 = taq-0.01 2{Wo-B,wt~  
    op.parent = parID `d75@0:  
    AddOperation eID, op 285
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    Print "Set pupil diameter = " & pupilDiam @@'nit  
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    'Update AZ Eye subassembly Description oS~}TR:}  
    eID = FindFullName( "Geometry.Arizona Eye" ) ao)Ck3]  
    GetEntity eID, entity +
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    entity.Description = "Accommodation = " & A & "D" M6J/mOVx5  
    SetEntity eID, entity ;KZrl`  
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    Update q.-y)C) ;  
    Print "DONE!" A:kkCG!~Nf  
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End Sub }ppVR$7]0  
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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： RXBb:f  
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Accommodation = 4 Diopters 3AK(dC[ri  
Pupil Diameter = 4 mm c\M#5+1j  
Set aqueous humor thickness = 2.81 , Hn7(^t  
Set anterior lens radius = 10.4 and conic constant = -2.375869 6MuWlCKF8  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 3=Z<wD s  
Set lens thickness = 3.927 Yy]T J  
Set lens index of refraction = 1.42672 \@i=)dA  
Set pupil diameter = 4 x
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DONE! "LOnDa7E^  
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