Arizona眼睛模型

; wHuL\   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。 [/#n+sz.A   *fd` .}   模型 c7r YG]   G~esSL^G/   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。 q',a7Tf:   Table 1. AZ眼睛模型的定义 0)2lBfHQ&   !-MG"\#Wq   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. dfJ7Dhn   A`N;vq,   光源 +mxYz#reX   ptDA))7M/   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。 t3s}U@(C   .`h+fqa   图1. 光源和提示信息使用 VR:b1XWX   z:fhq:R(   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。 L0_=R;.<   '\_)\`a|   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。 3o^V$N.   图2. 字母F光源的设定方法光 50R+D0^mh   &YMVoyVD   图3. 字母F在视网膜上位置点列图 WI~%n   ud#8`/!mq   视网膜的散射 eD(a +El}   Y zvtxX*   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 JWdG?[$   Q V 'y6m\   图4. 视网膜朗伯散射设定 ut,"[+J   ``z="oD   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。 JR>B<{xB   |$w-}$jq5   图5. 视网膜重点采样规格设定 S8cFD):q   P4AdfHk   脚本 "nefRz%j+   d!X?R}   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： UCWU|r<s,   图6. 用户对话框的创建与编辑 enrmjA&3   图7. 用户对话框编辑器 (1HN, iJy   Cwh;+3?C|   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。 lKwcT!Q4   余下的脚本计算与屈光度有关的所有参数。 b>(lF%M   7U7 i2 4   分析 E4.IS=4S   _t[%@G>P   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 ;(,Fe/wvC   图7. 字母F在视网膜上颜色分析 )gLasR.1   v%- V|L   脚本代码 LYFvzw>M   y$"L`*W   Option Explicit     'Remove this to enable non-dimensioned variables to be used. Ol@ZH_   ?!66yn   Dim entity As T_ENTITY |Wgab5D>V   Dim op As T_OPERATION ,'6GG+   Dim mat As T_MODELMATERIAL <>oW  f   Dim A As Double Y|~>(   Dim pupilDiam As Double D-!%L<<   Dim eID As Long E;Hjw0M'k   Dim parID As Long z~5'p(|@f   Dim count As Integer B;Z^.3   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double u5ygbCm   Dim tlens As Double, nlens As Double gD\}CxtG   Dim curv As Double, conic As Double u5_fM*Ka   Dim ok As Long 5S?yj   3Cl9,Z"&6$   Sub Main iT"Itz-^#   u\wd<<I']       '用户输入对话框 OXB-. <       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 jayoARUB           TextBox 220,21,40,21,.TextBox1 'default: 0 8IH gsW";           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 g1|c?#fwo           OKButton 40,91,90,21 -tdG}Gu           CancelButton 190,91,90,21 co80M;4           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 k N+(           TextBox 220,49,40,21,.TextBox2 'default: 4 ;p ('cwU%       End Dialog ZM?r1Z4       Dim dlg As UserDialog (ce NVo&   H/&Q,9sU21       ok = Dialog (dlg) -EaZ<d[|0   dFFqs&cQ       If ok=0 Then    'cancel button was pressed 0Kk*~gR?           Print "Execution cancelled." ]IV;>94[           End HWBom8u0       End If LH;G:   (^9M9+L[i       'Assign accommodation and pupil diameter & use defaults if field left empty Qg!*=<b       If dlg.TextBox1 = "" Then aO%FQ)BT           A = 0           'Default accommodation % 5gJ6>@6Z       Else B_2>Yt"           A = CDbl(dlg.TextBox1) nW_       End If ={'($t%|T   9Q/!%y%5       If dlg.TextBox2 = "" Then eb\`)MI/           pupilDiam = 4   'Default pupil diameter bicL%I2h       Else xk8p,>/           pupilDiam = CDbl(dlg.TextBox2) \k_3IP?o=       End If >}*jsqaVU   OvG0UXRU       Print " "  F`.7_D       Print "Accommodation = " & A & " Diopters" 55b |zf       Print "Pupil Diameter = " & pupilDiam & " mm" X)OP316yx   Uc0'XPo3I       ' Calculate new parameters with accommodation -RQQ|:O$       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness #UD   nn:pf1       Rant = 12.0 - 0.4*A                     'Radius of anterior lens Y{|yB       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens J*X.0&Toc   ^)l@7XxD       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens T+h{Aeg       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens reJ?38(   U&$]?3?       tlens = 3.767 + 0.04*A                  'Lens thickness MToQ8qKs   [frD L)       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 9z/_`Xd_   UO<claV       'Adjust parameters to account for accommodation 2 (//slP   Aq'E:/       '************************************************************************* l:yAgm`       'Aqueous thickness (Position of Lens) G5J ZB7C       '************************************************************************* [+,U0OV,       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) !bQ &n       GetCustomElement eID, entity "mDrJTWa   &(^u19TKl       parID = FindFullName( "Geometry.Arizona Eye" ) (kyo?3   `Kw8rG\]:       ' Delete any shift(s) in z t>@3 RBEK       count = 0 EoR6Rx@Z       While GetOperationCount(eID)>count 3#9r4;&           GetOperation eID, count, op 3|r!*+.           If op.Type="ShiftZ" Then aB6LAb2z;T               DeleteOperation eID,count [<a%\:c m4               count=count-1 0a6z"K}           End If E(+wl           count=count+1 N:jiZ)       Wend T8TsKjqOZ   (G%gVk]       'Set new shift in ~.`r(       op.Type = "ShiftZ" x0$:"68PW       op.val1 = taq i=H>D       op.parent = parID Le:mMd= G       AddOperation eID, op L9?/ -@M       Print "Set aqueous humor thickness = " & taq-0.55 SH$cn,3F8   UA4d|^ev       '************************************************************************* i3&B%JiLX       'Radius and conic constant of anterior lens '!h0![OH       '************************************************************************* C{i;spc!bi       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Bp{`%86SE       GetConic eID, entity, curv, conic ::R00gd   IBNQmVRrI       SetConic eID, entity, 1/Rant, CCant @mRrA#E#{       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 'Qq_Xn8   @:QdCG+       '************************************************************************* b ok 74U]       'Radius and conic constant of posterior lens 9`n)"r       '************************************************************************* }cK~=@7tK       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) v:Z4z6M-       GetConic eID, entity, curv, conic pW--^aHu   O0(Q0Ko       SetConic eID, entity, 1/Rpost, CCpost yO,`"Dc_0       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ~TFYlV   [xp,&       '************************************************************************* OPt;G,$ta       'Lens thickness (Position of posterior lens surface) a(DZGQ-as       '************************************************************************* DcR}pQ(e   S{(p<%)[       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) j484b2uj1   X8SRQO^       ' Delete any z-shift(s) QUZQY`'@       count = 0 e=jT]i*cU       While GetOperationCount(eID)>count [H:GKhPC`           GetOperation eID, count, op 3)c K*8#           If op.Type="ShiftZ" Then ss yd8LC#               DeleteOperation eID,count SM#S/|.]               count=count-1 ^0tf1pV2           End If u6Qf*_-K           count=count+1 fw|+7 O       Wend =_m9so   |~bR.IA       'Set new z-shift =6:L+V       op.Type = "ShiftZ" 'Ywpdzz[       op.val1 = tlens .F$|j1y       op.parent = parID hN_f h J       AddOperation eID, op mh#FYSp       Print "Set lens thickness = " & tlens L }jF#*Q%   +5t  bK       '************************************************************************* H1%[\X?=       'Lens index of refraction Jg|cvu-+       '************************************************************************* G>w?9:V}       eID = FindMaterial( "Lens" ) bA<AG*       GetModelMaterial eID, mat o%WjJ~!zL   t a4JWllf       mat.Nd = nlens }uI7\\S       SetModelMaterial eID, mat pba8=Z       Print "Set lens index of refraction = " & nlens :IVk_[s   E R]sDV       '************************************************************************* ZG@M%|>       'Pupil diameter pPyvR;NJ       '************************************************************************* 4de]?#=       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) =0PRAc   ?)' 2l6       'Adjust pupil diameter (trimming volume inner hole) 8L-4}!~C   JpxbB)/       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 5`E`Kb+@   *K,hrpYR       ' Adjust pupil location to just in front of the lens Z<ajET`)       parID = FindFullName( "Geometry.Arizona Eye" ) IObx^N_K       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) MZ5Y\-nq\       count = 0 Cl6m$YUt       While GetOperationCount(eID)>count @1qdd~B}           GetOperation eID, count, op .5Knbc           If op.Type="ShiftZ" Then 7Y32p'               DeleteOperation eID,count }{5mH:               count=count-1 f{igW?Ho           End If ss`P QN           count=count+1 I%9bPQ       Wend >sQ2@"y)s2       op.Type = "ShiftZ" `s`C{|wv       op.val1 = taq-0.01 3duG.iUlL       op.parent = parID fimb]C I|x       AddOperation eID, op ^Ue0mC7m   \9]I#Ih}M       Print "Set pupil diameter = " & pupilDiam Z6Nj<2u2   ]^:hyOK       'Update AZ Eye subassembly Description g@@&sB-A"       eID = FindFullName( "Geometry.Arizona Eye" ) 6x_T@       GetEntity eID, entity d/B'[Ur       entity.Description = "Accommodation = " & A & "D" ?C &x/2lt       SetEntity eID, entity i s L{9^   [dj5$l|       Update X"[dQ_o       Print "DONE!" E &7@#'l        Mlv<r=E   End Sub g4:VR:o    e=t<H"&   如果屈光度是4，光瞳直径是4，则会输出如下数据： Ys-Keyg   &P 8!]:   Accommodation = 4 Diopters ~->Hlxze'K   Pupil Diameter = 4 mm W.A1m4l58R   Set aqueous humor thickness = 2.81 E@w [&#   Set anterior lens radius = 10.4 and conic constant = -2.375869 8p (!]^z   Set posterior lens radius = -4.424557 and conic constant = -3.081019 OlMBMUR:   Set lens thickness = 3.927 $] @O/[   Set lens index of refraction = 1.42672 b'velj3A   Set pupil diameter = 4 aSOU#Csx   DONE!

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