Arizona眼睛模型

<Y$( lszT   人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 J;4aghzY   l,zhBnD   模型 j0s$}FPUI   dlIYzO<   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。 @PctBS<s   Table 1. AZ眼睛模型的定义 s[t<2)i   "fW }6pS   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. TQ5kM   \PcnD$L   光源 ,Q0H)//~   Ivj=?[c|   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。 `!AI:c*3p1   `csZ*$7   图1. 光源和提示信息使用 jL'`M%8O   a6 1!j>Kx   除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 kX8NRP W   xc\zRsY`   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 k%Vprc   图2. 字母F光源的设定方法光 Aa4Tq2G   n?;rWq"   图3. 字母F在视网膜上位置点列图 " 0m4&K(3,   5t"FNL <(M   视网膜的散射 7D4tuXUq2   \4^rb?B   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 c?u*,d) G   )*S:C    图4. 视网膜朗伯散射设定 %:zu68Q[   :tI F*pC   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 E)ZL+(   o. ;Vrc   图5. 视网膜重点采样规格设定 q=V'pML   [.1MElM   脚本 nosD1sS.K8   %^vT7c>   内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： M +r!63T   图6. 用户对话框的创建与编辑 ^|]Dg &N.   图7. 用户对话框编辑器 `fTM/"   T'@+MA) ~   如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 -THMTRFz   余下的脚本计算与屈光度有关的所有参数。 _#s,$K#   |K06H ?6X   分析 ~~ rR< re   \6 JOBR   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 y!.jpF'uI   图7. 字母F在视网膜上颜色分析 [nPs   s&(;   脚本代码 });Rjg   DQm%=ON7   Option Explicit     'Remove this to enable non-dimensioned variables to be used. VL$ T   OmO#} k<   Dim entity As T_ENTITY "cPg_-n   Dim op As T_OPERATION C?T\5}h   Dim mat As T_MODELMATERIAL &Xqxuy ]J   Dim A As Double 4n@lrcq(   Dim pupilDiam As Double ]b!n ;{5   Dim eID As Long EZ]4cd/i   Dim parID As Long Oo}h:3?   Dim count As Integer =I@t%Y   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double . Dr!\.hL   Dim tlens As Double, nlens As Double yXJ25Axb   Dim curv As Double, conic As Double YcN|L&R.   Dim ok As Long N8{jvat   <f>w"r   Sub Main >8>!wi9U   =GPXuo       '用户输入对话框 LV^^Bd8Ct       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 :*M?RL@j           TextBox 220,21,40,21,.TextBox1 'default: 0 K)7T]z`           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 8(L$a1#5W           OKButton 40,91,90,21 G?1GkR           CancelButton 190,91,90,21 .d]/:T -0           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 z'EQdQ)           TextBox 220,49,40,21,.TextBox2 'default: 4 ` kT\V'       End Dialog  vW1^       Dim dlg As UserDialog $3^M-w   p%I'd^}.!       ok = Dialog (dlg) lFnls6dp   _x,X0ncv]@       If ok=0 Then    'cancel button was pressed q!y.cyL           Print "Execution cancelled." yYA*5 7^A           End K ze?@*       End If {aY) Qv}   {dpC;jsW1       'Assign accommodation and pupil diameter & use defaults if field left empty Z-PBCU       If dlg.TextBox1 = "" Then R^l0Bu]X           A = 0           'Default accommodation djdTh +>28       Else  nqj(V           A = CDbl(dlg.TextBox1) e*7O!Z=O       End If ~)U50.CH   K%v:giN$l`       If dlg.TextBox2 = "" Then \,Y .5?           pupilDiam = 4   'Default pupil diameter 7g\v (P       Else $ZM'dIk?           pupilDiam = CDbl(dlg.TextBox2) 6e-ME3!<l       End If P0l fK}   ?+t;\       Print " " 8RMM97@1Q       Print "Accommodation = " & A & " Diopters" ,hn#DJ)       Print "Pupil Diameter = " & pupilDiam & " mm" ,*|Q=   ,a #>e       ' Calculate new parameters with accommodation t*IePz]/       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ):$KM{X   Ei!Z]jeK       Rant = 12.0 - 0.4*A                     'Radius of anterior lens |Ea%nghl       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens fsL9d}   t1w5U+z       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Kb%Y %j       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens x%viCkq   {-4+=7Sg1       tlens = 3.767 + 0.04*A                  'Lens thickness Bb/if:XS   ]Dq6 XR       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Fv^zSoi2   *yhA8fJ       'Adjust parameters to account for accommodation jIs>>   X _ZO)|       '************************************************************************* :uCwWv       'Aqueous thickness (Position of Lens) N~!, S;w       '************************************************************************* W.j^L;       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) }4C_r'd6       GetCustomElement eID, entity #[prG   w;O-ATUzN       parID = FindFullName( "Geometry.Arizona Eye" ) 6Z_V,LD9L   :nIMZRJ_!E       ' Delete any shift(s) in z xuXPVJdi       count = 0 5A0]+)5E8       While GetOperationCount(eID)>count KhR3$|fH<           GetOperation eID, count, op clvg5{^q[           If op.Type="ShiftZ" Then Qt.*Z;Gs               DeleteOperation eID,count dmF=8nff               count=count-1 +f/ I>9G           End If ?|5M'o|9           count=count+1 apL$`{>US       Wend \IL)~5d   ~5P9^`KNH       'Set new shift in K#OL/2^ 5       op.Type = "ShiftZ" ~@'wqGTp       op.val1 = taq |m's)       op.parent = parID nah?V" ?Y       AddOperation eID, op m*y&z'e\       Print "Set aqueous humor thickness = " & taq-0.55 :E")Zw&sW3   0|AgmW_7 .       '************************************************************************* W8& )UtWQ       'Radius and conic constant of anterior lens h.Qk{v       '************************************************************************* ?Bu*%+       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) );!ND%       GetConic eID, entity, curv, conic |ke0G   %+'Ex]B       SetConic eID, entity, 1/Rant, CCant QM(xMq       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant AS;Sz/YP   D\Ez~.H       '************************************************************************* i9ySD       'Radius and conic constant of posterior lens _^_3>}y5op       '************************************************************************* ](JrEg$K       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) yY8zT Wji_       GetConic eID, entity, curv, conic 6:8s,a3&[k   =`+D/ W\[Y       SetConic eID, entity, 1/Rpost, CCpost @rGY9%E       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost qx#M6\L!   dXTD8 )&       '************************************************************************* UwUHB~<oE       'Lens thickness (Position of posterior lens surface) ()aCE^C       '************************************************************************* wNmpUO ?   f"7MYw\       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) w+6P x#   )WoH>D       ' Delete any z-shift(s) ?|ZbQz(bL       count = 0 uw3vYYFX       While GetOperationCount(eID)>count 1m5l((d           GetOperation eID, count, op d[6 'w ?           If op.Type="ShiftZ" Then 6k hBT'n               DeleteOperation eID,count ]T)N{"&N/               count=count-1 y,:WLk~           End If n3p@duC4           count=count+1 T`e`nQ0nn       Wend RI*n]HNgy+   ]$2 yV&V&       'Set new z-shift &5y       op.Type = "ShiftZ" aL:|Dr3SX       op.val1 = tlens /phMrL=       op.parent = parID v*V(hMy       AddOperation eID, op @XJ7ff&       Print "Set lens thickness = " & tlens a]p9[Nk   BWxfY^,'&6       '************************************************************************* ?kR1T0lKkE       'Lens index of refraction OJu>#        '************************************************************************* ?pZ"7kkD       eID = FindMaterial( "Lens" ) S TWH2_`       GetModelMaterial eID, mat pFH.beY   \a+Q5g       mat.Nd = nlens ~Eg]Auk7       SetModelMaterial eID, mat {m*lt3$k       Print "Set lens index of refraction = " & nlens P;.roD9   (#y2RF8j       '************************************************************************* V.{HMeE4       'Pupil diameter R3G\Gchd       '************************************************************************* &pY'       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Tw';;euw   -+[Lc_oNPx       'Adjust pupil diameter (trimming volume inner hole) *+*W# de.   [2,D]e       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 81EEYf   g?80>-!bF       ' Adjust pupil location to just in front of the lens  Gy\]j       parID = FindFullName( "Geometry.Arizona Eye" ) e .vt"eRB       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ZP~H!       count = 0 HN7tIz@Frc       While GetOperationCount(eID)>count 3:GwX4yW           GetOperation eID, count, op XQ=%a5w           If op.Type="ShiftZ" Then q;[HUyY,               DeleteOperation eID,count {_b2!!p               count=count-1 )jXKPLj           End If curYD~7           count=count+1 ]){ZL       Wend K+|XI|1p       op.Type = "ShiftZ" F^/KD<cgK       op.val1 = taq-0.01 ?lkB{-%rQ       op.parent = parID s=:)!M.i       AddOperation eID, op ulzX$   d:hnb)I$*       Print "Set pupil diameter = " & pupilDiam `xx.,;S   B9|s`o)!       'Update AZ Eye subassembly Description 693"Pg8b       eID = FindFullName( "Geometry.Arizona Eye" ) uD(C jHM>       GetEntity eID, entity D]_6OlIE#'       entity.Description = "Accommodation = " & A & "D" v' t'{g%       SetEntity eID, entity >>$L vQ   kBqgz|jE%       Update j_5&w Znq       Print "DONE!" ?5CE<[        ?#GTD?3d   End Sub F5X9)9S   YZ<zlU   如果屈光度是4，光瞳直径是4，则会输出如下数据： d-b<_k{p   1Du5Z9AM   Accommodation = 4 Diopters 8?8V;    Pupil Diameter = 4 mm tf6-DmMH   Set aqueous humor thickness = 2.81 \)5mO 8w   Set anterior lens radius = 10.4 and conic constant = -2.375869 sSfP.R   Set posterior lens radius = -4.424557 and conic constant = -3.081019 7vXP|8j   Set lens thickness = 3.927 p>eYi \'   Set lens index of refraction = 1.42672 7zx xO|p[   Set pupil diameter = 4 lv?`+tU2_   DONE!

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