Arizona眼睛模型

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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。 M2|!,2
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模型 9zb1t1[W
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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。 h@Ea5x

Table 1. AZ眼睛模型的定义
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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. Lo%vG{yTr
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光源 @k&6\1/U
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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。 1oej<67PdJ
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图1. 光源和提示信息使用
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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。 !i)!|9e
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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。 6X*vCylI

图2. 字母F光源的设定方法光 wn5OgXxG<

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图3. 字母F在视网膜上位置点列图
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视网膜的散射 ID2->J
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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。 .oyAi||
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图4. 视网膜朗伯散射设定
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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。 +PjTT6
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图5. 视网膜重点采样规格设定
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脚本 \Nt 5TG_
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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： T;92M}\

图6. 用户对话框的创建与编辑
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图7. 用户对话框编辑器
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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。 }#FV{C]
余下的脚本计算与屈光度有关的所有参数。 '#f<wfn
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分析 |reA`&<q
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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。 9r].rzf9

图7. 字母F在视网膜上颜色分析
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脚本代码 >[;W~*
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. _ p\L,No
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Dim entity As T_ENTITY !i;6!w
Dim op As T_OPERATION ~S/oW89
Dim mat As T_MODELMATERIAL mH$tG $
Dim A As Double eTa_RO,x
Dim pupilDiam As Double ty,oj33
Dim eID As Long ^/"}_bR
Dim parID As Long @ b!]Jw
Dim count As Integer VvyRZMR
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double kkq1:\pZ]a
Dim tlens As Double, nlens As Double \jiE:Qt
Dim curv As Double, conic As Double GOc
Dim ok As Long INN}xZ
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Sub Main ..}P$
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    '用户输入对话框 oVvA`}
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 +l7)7qKx
        TextBox 220,21,40,21,.TextBox1 'default: 0 ;bE/(nz M
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 PR@6=[|d
        OKButton 40,91,90,21 ZM.'W}J{*
        CancelButton 190,91,90,21 #d@wjQ0DW
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Ol>q(-ea
        TextBox 220,49,40,21,.TextBox2 'default: 4 U!(.i1^n
    End Dialog 5s[nE\oaG
    Dim dlg As UserDialog (Mk7"FC7
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    ok = Dialog (dlg) 1"H;Tr|
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    If ok=0 Then    'cancel button was pressed pa!BJ]~
        Print "Execution cancelled." Gm|-[iUTG]
        End `WayR^9
    End If bXs=<`>
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    'Assign accommodation and pupil diameter & use defaults if field left empty VfcIR(
    If dlg.TextBox1 = "" Then 'S_i6K
        A = 0           'Default accommodation uN`/&_$c
    Else nJ;^Sz17Q
        A = CDbl(dlg.TextBox1) |n26[=\B
    End If $r!CQ2S
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    If dlg.TextBox2 = "" Then '`2KLO>!
        pupilDiam = 4   'Default pupil diameter E#J})cPzw
    Else fu5L)P^T
        pupilDiam = CDbl(dlg.TextBox2) a:cci?cb
    End If ?9~^QRLT
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    Print " " yD3}USw
    Print "Accommodation = " & A & " Diopters" ME)Tx3d
    Print "Pupil Diameter = " & pupilDiam & " mm" 1wR[nBg*|
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    ' Calculate new parameters with accommodation E.K^v/dNdq
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness EOB8|:*
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [M\ an6h6O
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens hN3FH#YO
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens & P-8_I
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 0-Mzb{n5
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    tlens = 3.767 + 0.04*A                  'Lens thickness {+67<&g
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction r07u6OA
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    'Adjust parameters to account for accommodation 4}H+hk8-
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    '************************************************************************* hZJ~zx~
    'Aqueous thickness (Position of Lens) J p?XV<3Z
    '************************************************************************* m4/qxm"Dx:
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,6>3aD1w~q
    GetCustomElement eID, entity `p()ko
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    parID = FindFullName( "Geometry.Arizona Eye" ) ZO<,V
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    ' Delete any shift(s) in z &ksuk9M
    count = 0 >PA*L(Dh%
    While GetOperationCount(eID)>count wMVUTm
        GetOperation eID, count, op a}yb~:TC
        If op.Type="ShiftZ" Then c>LP}PGk
            DeleteOperation eID,count EVPQe-
            count=count-1 5MnP6(3$
        End If <st<oR'
        count=count+1 G0 )[(s
    Wend Hhknjx
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    'Set new shift in \ptO4E
    op.Type = "ShiftZ" CP7Fe{P
    op.val1 = taq @;4;72@O
    op.parent = parID 30sJ"hF9
    AddOperation eID, op V#ELn[k
    Print "Set aqueous humor thickness = " & taq-0.55 VEgtN}
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    '************************************************************************* ]yPK}u
    'Radius and conic constant of anterior lens e4z~
    '************************************************************************* FSMM
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) `H! (hMMV
    GetConic eID, entity, curv, conic <odi>!ViH
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    SetConic eID, entity, 1/Rant, CCant T1d@=&0"
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant U"r*kO%
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    '************************************************************************* 9Vt ^q%DC
    'Radius and conic constant of posterior lens G=cRdiy`C
    '************************************************************************* x {NBhq(4
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) .) Ej#mk
    GetConic eID, entity, curv, conic $4{sPHi)I
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    SetConic eID, entity, 1/Rpost, CCpost %tVU Rj
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost + +L7*1t
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    '************************************************************************* 76w[X=Fv
    'Lens thickness (Position of posterior lens surface) 2PQBUq
    '************************************************************************* _x.2&S89
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) {bXN[=j
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    ' Delete any z-shift(s) 6:2*<
    count = 0 <SNr\/aCRi
    While GetOperationCount(eID)>count 1J!v;Y\\
        GetOperation eID, count, op Tr?p/9.m
        If op.Type="ShiftZ" Then toY_1
            DeleteOperation eID,count 8ae`V!5
            count=count-1 PlB3"{}0Q
        End If ZjxF@`H
        count=count+1 4#(/{6J
    Wend D|5mNX%e
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    'Set new z-shift i431mpMa
    op.Type = "ShiftZ" *P'X[z
    op.val1 = tlens 8]#FvgX
    op.parent = parID X`g<"Ka
    AddOperation eID, op v`oilsrc
    Print "Set lens thickness = " & tlens 8[@,i|kgg0
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    '************************************************************************* /H<{p$Wd
    'Lens index of refraction FsqH:I4O
    '************************************************************************* Zz} o t
    eID = FindMaterial( "Lens" ) r%;|gIky
    GetModelMaterial eID, mat (A?>U_@
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    mat.Nd = nlens P.YT/
    SetModelMaterial eID, mat "[ S[vkI
    Print "Set lens index of refraction = " & nlens Uc!k)o#=
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    '************************************************************************* !mK()#6
    'Pupil diameter {mU%.5
    '************************************************************************* W7!Rf7TK
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Py*WHHO
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    'Adjust pupil diameter (trimming volume inner hole) b,Eq-Z;
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" |r+ x/,2-
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    ' Adjust pupil location to just in front of the lens wbWC &X.
    parID = FindFullName( "Geometry.Arizona Eye" ) SXsszb:_
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) gbMA-r:IC
    count = 0 {U-z(0
    While GetOperationCount(eID)>count ;C-ds
        GetOperation eID, count, op Ho(MO!(
        If op.Type="ShiftZ" Then NzZ(Nz5
            DeleteOperation eID,count UG.:D';3,
            count=count-1 `n6cpX5
        End If fmYx
        count=count+1 tzN9d~JZ
    Wend ~xG/yPl
    op.Type = "ShiftZ" n_{&dVE
    op.val1 = taq-0.01 P:g!~&Q
    op.parent = parID q2#Ebw%]
    AddOperation eID, op 9(fh+
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    Print "Set pupil diameter = " & pupilDiam RV@B[:
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    'Update AZ Eye subassembly Description "6]oi*_8
    eID = FindFullName( "Geometry.Arizona Eye" ) ~d&&\EZ
    GetEntity eID, entity M"]?'TMfXc
    entity.Description = "Accommodation = " & A & "D" %x#S?GMV<
    SetEntity eID, entity eLT3b6'"?
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    Update Q=!QCDO(
    Print "DONE!" F$>#P7ph\a
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End Sub H.?`90IQ
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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： ~7aD#`amU
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Accommodation = 4 Diopters &=t~_ Dc
Pupil Diameter = 4 mm yVzV]&k
Set aqueous humor thickness = 2.81 ;|T|*0vY[
Set anterior lens radius = 10.4 and conic constant = -2.375869 Kez0Bka
Set posterior lens radius = -4.424557 and conic constant = -3.081019 R)d_0Ng
Set lens thickness = 3.927 \>su97
Set lens index of refraction = 1.42672 #l>r9Z71
Set pupil diameter = 4 `Zp*?
DONE!
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