Arizona眼睛模型

l]wLQqoO   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。 %RtL4"M2j   NnHaHX   模型 }MMKOr(   S{&%tj~U   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。 %au>D   Table 1. AZ眼睛模型的定义 \7qj hA@   `!I/6d?A   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. ?3 2~%?m   N]iarYc   光源 @#W4?L*D   J>T98y/))   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。 ub>:dNBN   aLm~.@Q   图1. 光源和提示信息使用 GEVDXx>@   ai?J    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。 oVHe<zE.   Y0lLO0'   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。 iZnLgkk@   图2. 字母F光源的设定方法光 !^MwE]   mUP!jTF   图3. 字母F在视网膜上位置点列图 :PN%'~}n   s Y1@~v   视网膜的散射 [c1Gq)ht   yZp/P%y   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。 o@360#njF   .J @mpJdY   图4. 视网膜朗伯散射设定 ESoC7d&.K{   Gq[5H(0/c   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。 P(@Q[XQ2   ^}vf   图5. 视网膜重点采样规格设定 ?nL , Otz   {#?|&n<   脚本 aizws[C   _>`9]6\&   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： ;/4x.t#b   图6. 用户对话框的创建与编辑 T&6>Eb0{   图7. 用户对话框编辑器 t`hes $E   N\tFK*U^I   如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 I*>q7Hsu   余下的脚本计算与屈光度有关的所有参数。 O[U`(A:   nJv=kk1|o   分析 Y$,~"$su|   >JA-G@3i   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 MRo_A n+   图7. 字母F在视网膜上颜色分析 Io  IhQ   ZZHQ?p-   脚本代码 \5<Z[#{   /=za m3kd   Option Explicit     'Remove this to enable non-dimensioned variables to be used. k&5T-\q   ZVdQ$   Dim entity As T_ENTITY ,37<FXX,   Dim op As T_OPERATION kFkI[WKyZ   Dim mat As T_MODELMATERIAL 32aI0CT   Dim A As Double _(:$ :*@   Dim pupilDiam As Double Zz:%KUl3   Dim eID As Long q6E'W" Q   Dim parID As Long 1]0;2THx   Dim count As Integer ;m.6 ~A   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 0'A"]6   Dim tlens As Double, nlens As Double q4!\^HwQ   Dim curv As Double, conic As Double ) 5Ij   Dim ok As Long m0.g}N-w   bnvY2-O6   Sub Main nLk`W"irM   J_yXL7d       '用户输入对话框 Z 369<       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 /TB{|_HbW           TextBox 220,21,40,21,.TextBox1 'default: 0 vAop#V           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 YE*|KL^           OKButton 40,91,90,21 Pz D30VA           CancelButton 190,91,90,21 FY)]yz           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 F}[!OYyg           TextBox 220,49,40,21,.TextBox2 'default: 4 zNo"P[J8       End Dialog :}#)ipr       Dim dlg As UserDialog \pI {b9   RSB+Saf.8       ok = Dialog (dlg) 4|Y1W}!0/   oz ]3 Tx       If ok=0 Then    'cancel button was pressed iC!6g|]X           Print "Execution cancelled." ^  ~1QA           End S" ^'ksL\       End If _ 3>E+9TQ   >e-0A       'Assign accommodation and pupil diameter & use defaults if field left empty 16@ <G       If dlg.TextBox1 = "" Then hRB ?NM           A = 0           'Default accommodation O+<+yQl       Else z"QtP[_m           A = CDbl(dlg.TextBox1) L|s\IM1g       End If Pq{p\Qkj   y>h9:q|       If dlg.TextBox2 = "" Then J2oh#TGp           pupilDiam = 4   'Default pupil diameter ?0sTx6x@       Else ;[P>           pupilDiam = CDbl(dlg.TextBox2) d>MDC . j       End If 7l*vmF6Z   :p)^+AF"5       Print " " };P=|t(r       Print "Accommodation = " & A & " Diopters" L"S2+F)n       Print "Pupil Diameter = " & pupilDiam & " mm" qZV|}M>P)   v}AjW%rB       ' Calculate new parameters with accommodation WL,2<[)Ew       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness (I jM   5{DwD{Q       Rant = 12.0 - 0.4*A                     'Radius of anterior lens jyyig%       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens p9\*n5{   ([rSYKpi       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens :#n>Q1}x       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens `0_ Y| 4KB   }C/+zF6 q       tlens = 3.767 + 0.04*A                  'Lens thickness #< :`:@2   +`mI\+y,       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction *h).V&::O   9FNsW$b?       'Adjust parameters to account for accommodation bF,.6iKI   @ %q>Jd       '************************************************************************* b&_Ifx_YF       'Aqueous thickness (Position of Lens) o>yXEg       '************************************************************************* k*,+ag*j       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) {+{p.       GetCustomElement eID, entity _"t>72 `   L+@X]OW8       parID = FindFullName( "Geometry.Arizona Eye" ) BKE?o^03   NZ!I >       ' Delete any shift(s) in z w0H#M)c       count = 0 'q}f3u >       While GetOperationCount(eID)>count "j8=%J{           GetOperation eID, count, op H=Cj/jE           If op.Type="ShiftZ" Then #D{Eq8dp               DeleteOperation eID,count =h ~n5wQG               count=count-1 $XkO\6kh           End If Gp)J[8j           count=count+1 >YF=6zq.`       Wend E&@#*~    }ksp(.}G       'Set new shift in q j9q       op.Type = "ShiftZ" WMWMb3       op.val1 = taq &U}8 @;       op.parent = parID iG~&uEAJ       AddOperation eID, op #QSSpsF@       Print "Set aqueous humor thickness = " & taq-0.55 Q^@7Yg@l   JxLfDr,dy       '************************************************************************* TVSCjI       'Radius and conic constant of anterior lens vMJ(Ll7/       '************************************************************************* 4Xt`L"f       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) /<k5"C%z       GetConic eID, entity, curv, conic U:c0s   ^si[L52BZ       SetConic eID, entity, 1/Rant, CCant 1:@ScHS       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Lh.-*H   f:~$x       '************************************************************************* @B(E&       'Radius and conic constant of posterior lens Q%J,: J       '************************************************************************* kr |k \       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) El :%\hGy       GetConic eID, entity, curv, conic R2 J A(Hn   y;<}`       SetConic eID, entity, 1/Rpost, CCpost ovXk~%_       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost [EZ=tk   tw\1 &*:       '************************************************************************* R>;&4Sjr       'Lens thickness (Position of posterior lens surface) ObS#aRq       '************************************************************************* K3,PmI&W   Bm%|W QK       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) co^h2b   8?: 2<       ' Delete any z-shift(s) ~.0'v [N       count = 0 ^L7!lzyo       While GetOperationCount(eID)>count )vVf- zU           GetOperation eID, count, op +KNd%AJ           If op.Type="ShiftZ" Then JV'aqnb.8\               DeleteOperation eID,count fM*?i"j;Y               count=count-1 "^wIoJ6H'           End If 3/]FT#l]i           count=count+1 C|3cQ{       Wend /_Ku:?{   \n^[!e"`       'Set new z-shift Q|S>C%4?       op.Type = "ShiftZ" k9:|CEP       op.val1 = tlens C=cn.CX       op.parent = parID 2cRru]VZ5       AddOperation eID, op C-h?#/#?y       Print "Set lens thickness = " & tlens *n[BBz   AP1ZIc6       '************************************************************************* A:yql`&s       'Lens index of refraction $\~cWpv       '************************************************************************* R(cg`8       eID = FindMaterial( "Lens" ) eQn[       GetModelMaterial eID, mat KU+\fwYpnk   p0]\QM l1       mat.Nd = nlens IA]wO%c       SetModelMaterial eID, mat u&UmI-}       Print "Set lens index of refraction = " & nlens 83{P7PBQ;]   <8Nr;96 IA       '************************************************************************* f\.y z[       'Pupil diameter gG}H5uN       '************************************************************************* kp}[nehF       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 8ZM#.yBB   *rHz/& ,       'Adjust pupil diameter (trimming volume inner hole) v9S=$Aj   C8 |#       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Q6e7Z-8   6-J}ZfGj       ' Adjust pupil location to just in front of the lens RO%M9LISI       parID = FindFullName( "Geometry.Arizona Eye" ) - _6`0       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) dG]B-(WTC       count = 0 9PV+Kr!c5I       While GetOperationCount(eID)>count EBz4k)@m           GetOperation eID, count, op ^yq}>_           If op.Type="ShiftZ" Then :M f8q!Q'               DeleteOperation eID,count cs9h\]ZA               count=count-1 kN8B,           End If 1,M m+_)B           count=count+1 2k^rZ^^"       Wend )|k#cT{=M       op.Type = "ShiftZ" ~w|h;*Bj       op.val1 = taq-0.01 yG7H>LF?8       op.parent = parID <p/2hHfiD       AddOperation eID, op $?]`2*i   KRcB_(       Print "Set pupil diameter = " & pupilDiam q5'G]j{,Z   cL;%2TMk       'Update AZ Eye subassembly Description ~K<h~TNP       eID = FindFullName( "Geometry.Arizona Eye" ) HuU$x;~       GetEntity eID, entity @o^$/AE?       entity.Description = "Accommodation = " & A & "D" pL`Q+}c}       SetEntity eID, entity J[hmY=,   vTK8t:JQ~       Update }Bsh!3D<.       Print "DONE!" gTOx|bx        H-v[ShE   End Sub B7|%N=S%/   #W3H;'~/5   如果屈光度是4，光瞳直径是4，则会输出如下数据： r `n|fD.   WG,1%=M@   Accommodation = 4 Diopters @U1|?~M%s   Pupil Diameter = 4 mm [6JDS;MIN   Set aqueous humor thickness = 2.81 [)GRP   Set anterior lens radius = 10.4 and conic constant = -2.375869 y%61xA`#   Set posterior lens radius = -4.424557 and conic constant = -3.081019 D M+MBK   Set lens thickness = 3.927 _5~|z$GW   Set lens index of refraction = 1.42672 Fw{@R Qf8   Set pupil diameter = 4 n8_X<jIp3   DONE!

8sc2r

ytjZ7J['{