Arizona眼睛模型

FBpf_=(_1   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。 Rckqr7q   AyZL(   模型 *C*n(the   b]s.h8+v;   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。 $i&u\iL   Table 1. AZ眼睛模型的定义 Y>*{(QD   0q`n]NM   在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 6XPf0Gl   o@6:|X)7   光源 W%@L7xh   ZW\}4q;[A   多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 0U'g2F>{   /*DC`,q   图1. 光源和提示信息使用 C FY3D|   q1QrtJFPG   除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 z>$AZ>t%J$   *I7$\0Q   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。 L1;IXCc=   图2. 字母F光源的设定方法光 R(Y4nw+Y-   p3Uus''V4   图3. 字母F在视网膜上位置点列图 B\BxF6 y   Ym~*5|   视网膜的散射 I9GRSm;0<   5(kRFb'31F   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。 DuJbWtA   <t[WHDO`   图4. 视网膜朗伯散射设定 ,gHgb   cX'&J_T+   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。 l!z0lh-J   YGb&mD   图5. 视网膜重点采样规格设定 /I@nPH<y   wmu#@Hf/[h   脚本 p:]kH   NYbeIfL   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： O+U9 p    图6. 用户对话框的创建与编辑 FL-yt   图7. 用户对话框编辑器 @m14x}H   ~$7fU   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。 ?rqU&my S   余下的脚本计算与屈光度有关的所有参数。 yj!4L&A   S`ms[^-q*   分析 GY9CU=-   'Dl31w%:   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 $ 7%e|0jC   图7. 字母F在视网膜上颜色分析 w+<` >   871taL =   脚本代码 D&KD5_Sw   =lIG#{`Q   Option Explicit     'Remove this to enable non-dimensioned variables to be used. JGjqBuz#A*   kI5`[\   Dim entity As T_ENTITY  h"<-^=b   Dim op As T_OPERATION Cf#[E~24   Dim mat As T_MODELMATERIAL `em}vdY   Dim A As Double J)R;NYl   Dim pupilDiam As Double >gNVL (   Dim eID As Long 5AV5`<r.   Dim parID As Long m4FT^^3yE   Dim count As Integer %j4   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 5e^t;   Dim tlens As Double, nlens As Double bnS"@^M   Dim curv As Double, conic As Double E;7vGGf]   Dim ok As Long D;%(Z!   at_~b Ox6X   Sub Main l*;Isz:   FSnF>3kj-       '用户输入对话框 vvEr}G       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ,U9gg-.Lp           TextBox 220,21,40,21,.TextBox1 'default: 0 Hk)IV"[R           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 |fYr*8rH           OKButton 40,91,90,21 |> mx*G           CancelButton 190,91,90,21 =?Y%w%2           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 .6I*=qv)NA           TextBox 220,49,40,21,.TextBox2 'default: 4 e$krA! zN       End Dialog 4,D$% .       Dim dlg As UserDialog #sLyU4QV   ~s_n\r&23       ok = Dialog (dlg) qF9z@a   JVO,@~~       If ok=0 Then    'cancel button was pressed L~nVoKY*V           Print "Execution cancelled." L8"0o 0-           End nqX)+{wAXe       End If V[&4Km9C   (7 i@@       'Assign accommodation and pupil diameter & use defaults if field left empty D@:w/W       If dlg.TextBox1 = "" Then I"/p^@IX           A = 0           'Default accommodation yHS=8!        Else SM3Q29XIw           A = CDbl(dlg.TextBox1) G,+-}~$_       End If >_9w4g_<   .GG6wL<$?       If dlg.TextBox2 = "" Then 4L'dV           pupilDiam = 4   'Default pupil diameter g]B! 29M       Else .QRa{l_)           pupilDiam = CDbl(dlg.TextBox2) cB~D3a0Th       End If R0>GM`{   6$#p}nE       Print " " :Osw4u]JXd       Print "Accommodation = " & A & " Diopters" `?Wy;5-       Print "Pupil Diameter = " & pupilDiam & " mm" nt$VH   0 t.'?=       ' Calculate new parameters with accommodation :G+8%pUX]       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness y#%*aV}|B   :__z?<?(       Rant = 12.0 - 0.4*A                     'Radius of anterior lens [ 0?*J<d       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens F'eV%g   &PJ&XTR       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens a`]Dmw8@       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ;|(_;d   |etA 2"r&       tlens = 3.767 + 0.04*A                  'Lens thickness ]w2nVC3   //9M~qHa"       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction N_AAhD   AcF6p)@_       'Adjust parameters to account for accommodation ivy+e-)    83rtQ;L       '************************************************************************* E+>$@STv#       'Aqueous thickness (Position of Lens) K5; /       '************************************************************************* "u#T0       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 9 gt$z}oU       GetCustomElement eID, entity N_#QS}H   mIJYe&t7)       parID = FindFullName( "Geometry.Arizona Eye" ) .Sz<%d7XIQ   3ya_47D       ' Delete any shift(s) in z .nXOv]       count = 0 GR@jn]50       While GetOperationCount(eID)>count /5@4}m>Z@           GetOperation eID, count, op ``l7|b jJ           If op.Type="ShiftZ" Then P2lDi!q|               DeleteOperation eID,count zR)9]p J-               count=count-1 a>1_|QB.           End If Z_Tu* F           count=count+1 7#\\Ava$T       Wend 7WuhYJbf   Aqi9@BH       'Set new shift in i+`N0!8lY       op.Type = "ShiftZ" K0681_bp       op.val1 = taq 9?4EM^-       op.parent = parID B2}|b^'I       AddOperation eID, op 9rO,h|L       Print "Set aqueous humor thickness = " & taq-0.55 e!+_U C   T@V<J'       '************************************************************************* :%&~/@B       'Radius and conic constant of anterior lens 0~.OMG:=       '************************************************************************* n*7Ytz3#'       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Wnp\yx`       GetConic eID, entity, curv, conic pf_(?\oz>   .i^aYbB$X       SetConic eID, entity, 1/Rant, CCant -kFPmM;       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant %hEhZW{:   e MX?x7       '************************************************************************* =!@5!       'Radius and conic constant of posterior lens !F@9xG       '************************************************************************* t-, =sV       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) *b< a@       GetConic eID, entity, curv, conic -F&4<\=+   AD_aI %7       SetConic eID, entity, 1/Rpost, CCpost V(-=@UW       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 4T]n64Yid   d&z^u.SY       '************************************************************************* #M9rt~4       'Lens thickness (Position of posterior lens surface) ?8{x/y:       '************************************************************************* Tc{n]TV   FZUN*5`       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) @wzzI 7}C   _{d0Nm       ' Delete any z-shift(s) G-vBJlt=t       count = 0 Iuh1tcc       While GetOperationCount(eID)>count Sqt'}           GetOperation eID, count, op rKK{*%n           If op.Type="ShiftZ" Then B~[}E]WEK               DeleteOperation eID,count y@\R$`0J               count=count-1 WyO7,Qr\           End If !!jitFHzb           count=count+1 )Ha`>       Wend Wr3).m52}P   )QeXA)       'Set new z-shift y;M}I8W[       op.Type = "ShiftZ" >4c7r~\k       op.val1 = tlens nDt1oM H       op.parent = parID YPq4VX,       AddOperation eID, op mJj [f8       Print "Set lens thickness = " & tlens BCrX>Pp}r   F4Jc7k2       '************************************************************************* ]Wn^m+       'Lens index of refraction Py&DnG'H       '************************************************************************* E{Gkq:       eID = FindMaterial( "Lens" ) f&z@J,_=       GetModelMaterial eID, mat Z= 'DV1A$,   Sr9)i8x{       mat.Nd = nlens I04GQql       SetModelMaterial eID, mat {giKC)!       Print "Set lens index of refraction = " & nlens Y,?!"   =V)88@W       '************************************************************************* `{1&*4!       'Pupil diameter e58       '************************************************************************* C4Tn       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) {~Q9jg(A   \R m2c8Z2       'Adjust pupil diameter (trimming volume inner hole) v#HaZT]u   J ejDF*Q       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" H[cHF   M;14s*g       ' Adjust pupil location to just in front of the lens E[z8;A^:0       parID = FindFullName( "Geometry.Arizona Eye" ) O%w"bEr)N       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) _tl,-}~       count = 0 SO~]aFoYt       While GetOperationCount(eID)>count -G!W6$Y           GetOperation eID, count, op Q|!}&=           If op.Type="ShiftZ" Then V_>)m3zsL               DeleteOperation eID,count stb)Tl^               count=count-1 DE0gd ux8           End If w6B'&           count=count+1 %lr<;        Wend Ps0g       op.Type = "ShiftZ" SkmLX@:(       op.val1 = taq-0.01 GaD]qeS-K       op.parent = parID JTK0#+?       AddOperation eID, op lzKJ y   ]m>N!Iu       Print "Set pupil diameter = " & pupilDiam fn!(cE|`E   ?gq',FFDq       'Update AZ Eye subassembly Description m]Sv>|       eID = FindFullName( "Geometry.Arizona Eye" ) ))pp{X2m       GetEntity eID, entity FMuakCic5       entity.Description = "Accommodation = " & A & "D" QGWfF,q       SetEntity eID, entity RR%[]M#_T   &TpzJcd"       Update (>E}{{>2r       Print "DONE!" 7 Q`'1oE?        ,>DaS(   End Sub #4?(A[]>H   eX+FtN   如果屈光度是4，光瞳直径是4，则会输出如下数据： 75O-%9lFF   |o:[*2-   Accommodation = 4 Diopters uV\ _j3,2   Pupil Diameter = 4 mm 3\=iB&Gf|   Set aqueous humor thickness = 2.81 <])w@QOA#   Set anterior lens radius = 10.4 and conic constant = -2.375869 AADvk_R   Set posterior lens radius = -4.424557 and conic constant = -3.081019 2'R&K   Set lens thickness = 3.927 rm-6Az V   Set lens index of refraction = 1.42672 ]h Dy]   Set pupil diameter = 4 Y|s?9'z   DONE!

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