Arizona眼睛模型

b)}+>Wx   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。 e-6w8*!i   v548ysE)   模型 CY"i-e"q<Q   5~VosUpe7   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。 z/|BH^V w   Table 1. AZ眼睛模型的定义 3(_!`0#F%   !q/5yEJ>h   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. D'i6",Z>   'p}`i/   光源 05e>\}{0   vgG}d8MW37   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。 %efGt6&   LJuW${Y   图1. 光源和提示信息使用 fEqC] *s   ZXXiL#^   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。 &"S/Lt   S7sb7c'4 k   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。 4O$2]D.\   图2. 字母F光源的设定方法光 g:~+Pe   3oBC    图3. 字母F在视网膜上位置点列图 #BJ\{"b_}z   zJl_ t0   视网膜的散射 otriif@+Z   3'#%c>_   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 9D_wG\g   \Ow,CUd   图4. 视网膜朗伯散射设定 __\P`S_   {8CWWfHCD   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 h_ ZX/k   W<'<'z5   图5. 视网膜重点采样规格设定 qo;)X0N   !#}>Hv^N   脚本 I'_v{k5ZI   zixEMi[8   内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： [MmM9J["   图6. 用户对话框的创建与编辑 UxqWnHH.`   图7. 用户对话框编辑器 TmP8q   i?>Hr|   如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 UKs$W`   余下的脚本计算与屈光度有关的所有参数。 Slx2z%'>   }~zO+Wf2   分析 @PXXt#   >>V&yJ_   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 i^/54   图7. 字母F在视网膜上颜色分析 qx%jAs+~   ]P3[.$z   脚本代码 fValSQc!U   vInFo.e[4   Option Explicit     'Remove this to enable non-dimensioned variables to be used. yYX : huw   >d%VDjk .   Dim entity As T_ENTITY Bl4 dhBZoO   Dim op As T_OPERATION fv?45f   Dim mat As T_MODELMATERIAL DTy/jaK   Dim A As Double jsm0kz   Dim pupilDiam As Double F6&P~H   Dim eID As Long Wo3'd|Y~i   Dim parID As Long Xp^$ E6YFy   Dim count As Integer 3+ asP&n   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double [4gjC   Dim tlens As Double, nlens As Double AU`OESSI   Dim curv As Double, conic As Double 4*8&[b   Dim ok As Long ZNy9_a:dX   "::9aYd!   Sub Main x]'H jTqX   =uc^433.       '用户输入对话框 V.j#E1P       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 8p,>y(o           TextBox 220,21,40,21,.TextBox1 'default: 0 ,.7vBt6 p           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 fLM.kCD?u           OKButton 40,91,90,21 vU9ek:.l           CancelButton 190,91,90,21 )@$ &FFIu           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 n)CH^WHL&           TextBox 220,49,40,21,.TextBox2 'default: 4 ZbyG*5iq       End Dialog E{oB2;P       Dim dlg As UserDialog ^0eO\wc?O   Hdna{@~       ok = Dialog (dlg) . f%vDBJS   \E&thp       If ok=0 Then    'cancel button was pressed JD-Becz           Print "Execution cancelled." !PI0oh           End [oJ& J>U'       End If !Sfe{/$w   B3.X}ys#       'Assign accommodation and pupil diameter & use defaults if field left empty ir+8:./6       If dlg.TextBox1 = "" Then *vD/(&pQ1:           A = 0           'Default accommodation j]Ua\|t       Else %&2B           A = CDbl(dlg.TextBox1) SZE`J:w       End If wOM<XhZ   fv/v|       If dlg.TextBox2 = "" Then VLx T"] f           pupilDiam = 4   'Default pupil diameter `W="g6(       Else m&ZJqsZIL           pupilDiam = CDbl(dlg.TextBox2) pKYLAt+^>       End If *NF&Y   %0 qc@4       Print " " 2X^iV09       Print "Accommodation = " & A & " Diopters" /t5g"n3       Print "Pupil Diameter = " & pupilDiam & " mm" )2toL5Q   W n6,U=$3       ' Calculate new parameters with accommodation 13\Sh       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness fGG 9zB6   sB8p( L       Rant = 12.0 - 0.4*A                     'Radius of anterior lens n }TTq6B       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens nE^wxtY   Ho>p ^p       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens VrudR#q       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ~{9x6<g!   FfjC M7?       tlens = 3.767 + 0.04*A                  'Lens thickness "LXXs0   {#0Tl       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ^`/V i   :nt}7Dn'       'Adjust parameters to account for accommodation EI<"DB   svF*@(-P#       '************************************************************************* Q.<giBh       'Aqueous thickness (Position of Lens) @ljZw(       '************************************************************************* Re7{[*Q4       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^?#@[4?"       GetCustomElement eID, entity 1RURZoL   1RmBtx\<       parID = FindFullName( "Geometry.Arizona Eye" ) e1oFnu2R   QZWoKGd}+       ' Delete any shift(s) in z $`ON!,oa       count = 0 RLv&,$$0       While GetOperationCount(eID)>count y+l<vJu           GetOperation eID, count, op $B*qNYpPy.           If op.Type="ShiftZ" Then EWSr@}2j .               DeleteOperation eID,count YHJ'               count=count-1 LZbRQ"!!o           End If FyQOa)5           count=count+1 G &m>Ov$#&       Wend _Wq7U1v `   kWI]f Z_n       'Set new shift in $&bU2]       op.Type = "ShiftZ" :u,2"]       op.val1 = taq 1a \=0=[       op.parent = parID Pxap;;\       AddOperation eID, op o@Dk%LxP       Print "Set aqueous humor thickness = " & taq-0.55 OX'/?B((   k&n\ =tKN       '************************************************************************* AX/=}G       'Radius and conic constant of anterior lens ]eY Qio!       '************************************************************************* ^.nwc#       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) h\Z3yAYd       GetConic eID, entity, curv, conic (M4]#5   .0rJIO       SetConic eID, entity, 1/Rant, CCant R9S7_u       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 9t,aT!f   Vx0MG{vG1       '************************************************************************* lv*Wnn@k       'Radius and conic constant of posterior lens  T]5U_AI@       '************************************************************************* E>o&GYc       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) t201ud2$       GetConic eID, entity, curv, conic ,"4X&>_f   [RroHXdk+       SetConic eID, entity, 1/Rpost, CCpost =f/avGX       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 0]f?Dx/8   \UVT_=Y       '************************************************************************* <h)deB+}       'Lens thickness (Position of posterior lens surface) Tom}sFl][       '************************************************************************* #MmmwPB_   MZgmv       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ={e#lC   5<0Yh#_       ' Delete any z-shift(s) &1\u#LU       count = 0 fSm?27_       While GetOperationCount(eID)>count aTmX!!           GetOperation eID, count, op ',v0vyO8           If op.Type="ShiftZ" Then 3/]f4D{MMY               DeleteOperation eID,count DR#3njjEC               count=count-1 sIP6GWK$           End If 9&?tQ"@x           count=count+1 +9&ulr       Wend Xmw2$MCB   6EW"8RG`       'Set new z-shift p;)klH@X       op.Type = "ShiftZ" Br?++\       op.val1 = tlens y0W`E/1t       op.parent = parID >-o?S O(M,       AddOperation eID, op YQlpk@X`2       Print "Set lens thickness = " & tlens :{e`$kz   ~}FLn9@*       '************************************************************************* ^+YGSg7       'Lens index of refraction >xk:pL*o`       '************************************************************************* JJ= ~o@|c       eID = FindMaterial( "Lens" ) #dXZA>b9       GetModelMaterial eID, mat `pn-fk   '8iv?D5M       mat.Nd = nlens Xqq?S       SetModelMaterial eID, mat @idp8J [td       Print "Set lens index of refraction = " & nlens oWn_3gzw;   W"DxIy       '************************************************************************* ?N9adL &b       'Pupil diameter $txWVjR?\       '************************************************************************* J0{WqA.P       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) *AJezhR   3n=cw2FG       'Adjust pupil diameter (trimming volume inner hole) ^!{ oAzy9   QyBK*uNdV       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" $(!D/bvJ   wHDFTIDI       ' Adjust pupil location to just in front of the lens e=NQY8?       parID = FindFullName( "Geometry.Arizona Eye" ) q,19NZ       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) <CdG[Ih       count = 0 o8yEUnqN       While GetOperationCount(eID)>count 3]5&&=#           GetOperation eID, count, op ^~hhdwu3a           If op.Type="ShiftZ" Then x#!{5;V&K               DeleteOperation eID,count 7~k~S>sO               count=count-1 D6@ 4           End If RI<Yg#           count=count+1 ~`Gcq"7,!       Wend 5>^ W}0s       op.Type = "ShiftZ" )QJU ]G       op.val1 = taq-0.01 "!4>gg3r       op.parent = parID T3PaG\5B       AddOperation eID, op e&VR>VJEA   f1,$<Y|qU       Print "Set pupil diameter = " & pupilDiam rSFXchD/   ^?l-YnQqm?       'Update AZ Eye subassembly Description L@x8hUG"       eID = FindFullName( "Geometry.Arizona Eye" ) sfBjA       GetEntity eID, entity 0OoO cc       entity.Description = "Accommodation = " & A & "D" R,b O{2O       SetEntity eID, entity 8;dbU*   \Q BpgMi(       Update "YJ;-$rb       Print "DONE!" J7aK3he        qS`|=5f   End Sub pDnFT2   }sN9QgE   如果屈光度是4，光瞳直径是4，则会输出如下数据： F7PZV+\   3Tte8]0   Accommodation = 4 Diopters <38@b ]+   Pupil Diameter = 4 mm "/]tFY%Y   Set aqueous humor thickness = 2.81 d?+oT0pCH   Set anterior lens radius = 10.4 and conic constant = -2.375869 N X#/1=   Set posterior lens radius = -4.424557 and conic constant = -3.081019 n fPl#]ef*   Set lens thickness = 3.927 f4;8?   Set lens index of refraction = 1.42672 OgpH{"   Set pupil diameter = 4 c#-97"_8   DONE!

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