Arizona眼睛模型

(H2ylMpQt   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。 _hWuAJ9Qy   ?N`qLGRm   模型 '9"%@AFxZ   3?  };   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。 (HPz   Table 1. AZ眼睛模型的定义 @wMQC\Z   &M$Bt} <   在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. Enu!u~1]F   [.ey_}X8   光源 %6N)G!P   FN>L7 *,0   多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 n 3h^VQ*]G   ^K"ZJ6?+1   图1. 光源和提示信息使用 }'v{dK   %pH)paRAP   除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 C/bxfp{?   27Cz1[oX   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 H<$pHyxU   图2. 字母F光源的设定方法光 @K7ebYr?   Etw~*   图3. 字母F在视网膜上位置点列图 Q*Y4m8wY   J}:&eS   视网膜的散射 D/e&7^iK   ;4l-M2   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。 s:3aRQ%   Qg[heND   图4. 视网膜朗伯散射设定 ::v;)VdX+*   ^)Smv\Md   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。 7,f:Qi@g   Wux0RF&   图5. 视网膜重点采样规格设定 axOi5   3xP~~j;7   脚本 :-(U%`a[   !X%S)VSMU   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： ES^NBI j5P   图6. 用户对话框的创建与编辑 #]k0Z~Bl   图7. 用户对话框编辑器 dJloH)uJZ>   h>~jQ&\M   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。 yq1Gqbh l   余下的脚本计算与屈光度有关的所有参数。 DE5d]3B   p@vpd   分析 AbL5 !'   @<|6{N<   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 :wFb5"   图7. 字母F在视网膜上颜色分析 ejP,29   d:A\<F   脚本代码 H3!,d`D.N   pi|\0lH6W   Option Explicit     'Remove this to enable non-dimensioned variables to be used. 52da]BW<   bh{E&1sLh   Dim entity As T_ENTITY f+{c1fb>s   Dim op As T_OPERATION 0Wjd-rzc,   Dim mat As T_MODELMATERIAL #c6ui0E%;t   Dim A As Double @mvIt   Dim pupilDiam As Double T@B"BoKU   Dim eID As Long ,NjX&A@   Dim parID As Long :8](&B68gE   Dim count As Integer #E*@/ p/   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double F(J\ct ha   Dim tlens As Double, nlens As Double :uOZjEZi   Dim curv As Double, conic As Double &\JK%X.Jlt   Dim ok As Long iU.!oeR?   SCgyp(   Sub Main KX0<j   xt?3_?1       '用户输入对话框 sGXp}{E9       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 fx]\)0n           TextBox 220,21,40,21,.TextBox1 'default: 0 OD{5m(JwL           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 P]|J?$1K           OKButton 40,91,90,21 QIR4<]/           CancelButton 190,91,90,21 t8L<x           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 K4iI:           TextBox 220,49,40,21,.TextBox2 'default: 4 <ED8"~_       End Dialog ~sZqa+jB0       Dim dlg As UserDialog );0<Odw%.   GwTT+       ok = Dialog (dlg) lo\:]/&6   (J6" ;       If ok=0 Then    'cancel button was pressed |Dl*w/n           Print "Execution cancelled." !S h^LYqn           End 6Hc H'nmeN       End If MDMtOfe|   k)?,xY\AV       'Assign accommodation and pupil diameter & use defaults if field left empty \;nD)<)J       If dlg.TextBox1 = "" Then 9zXu6<|qrL           A = 0           'Default accommodation \pjRv       Else 3$GY,B           A = CDbl(dlg.TextBox1) r^?)F?n!       End If | \ s2   N BV}4       If dlg.TextBox2 = "" Then !7ei1           pupilDiam = 4   'Default pupil diameter >t1_5       Else z7OZ4R:           pupilDiam = CDbl(dlg.TextBox2) J xA^DH       End If ;X?Ah   r]8wOu-'       Print " " 0_YxZS\       Print "Accommodation = " & A & " Diopters" y#hga5       Print "Pupil Diameter = " & pupilDiam & " mm" F{#N6,T   b:N^Fe       ' Calculate new parameters with accommodation ?b!CV        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness bBkm]  >   !!?+M @       Rant = 12.0 - 0.4*A                     'Radius of anterior lens \>*MMe       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 'Qm` A=   T0@](g       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens @4 zi]v       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 8>C; >v   />dB%*       tlens = 3.767 + 0.04*A                  'Lens thickness kx"hWG4   l 'AK       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 3::3r}g   y3 ({(URU       'Adjust parameters to account for accommodation ?aK'OIo   LK'S)Jk       '************************************************************************* 7 \7Brw4       'Aqueous thickness (Position of Lens) m#5|J@]       '************************************************************************* *G%1_        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) \_*?R,$3Y,       GetCustomElement eID, entity 1g~Dm}m   bE7(L $UF       parID = FindFullName( "Geometry.Arizona Eye" ) n/9 LRZD|w   JcvHJ0X~a       ' Delete any shift(s) in z ]jVIpGM       count = 0 R-r+=x&       While GetOperationCount(eID)>count KuIt[oM           GetOperation eID, count, op g|&.v2 '           If op.Type="ShiftZ" Then M iP[UCh               DeleteOperation eID,count SQO>}#qm               count=count-1 LY@1@O2@           End If ^@|<'g.R-           count=count+1 ,wwU` U       Wend VfL]O8P>   >,w \lf9       'Set new shift in T[Z <bW~0       op.Type = "ShiftZ" rd&*j^?       op.val1 = taq VYl_U?D       op.parent = parID ,\sR;=svK       AddOperation eID, op ZYwBw:y}y       Print "Set aqueous humor thickness = " & taq-0.55 ifJv~asp    .c=$ bQ>^       '************************************************************************* ^]#Ptoz^(l       'Radius and conic constant of anterior lens p\\P50(-       '************************************************************************* 8!`7-       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ,(@Y%UW:       GetConic eID, entity, curv, conic ;ZxK3/(7   ?MV[=LPL       SetConic eID, entity, 1/Rant, CCant ^F0k2 pB       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Gx(KN57D   Q{H!s_6iyv       '************************************************************************* x*,q Rew       'Radius and conic constant of posterior lens Ak\D6eHcB       '************************************************************************* !^Z[ z[       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) [3{:H"t       GetConic eID, entity, curv, conic k=h/i8i2z   7`uA       SetConic eID, entity, 1/Rpost, CCpost 2-"Lxe65f       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ),D`ZRXS   haEZp6Z       '************************************************************************* ohQz%?r       'Lens thickness (Position of posterior lens surface) )RAv[U1       '************************************************************************* mR"2   %T&&x2p^=?       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ;3.T* ?|o   V',m $        ' Delete any z-shift(s) 4 BE:&A       count = 0 YobC'c\~9       While GetOperationCount(eID)>count 0]:*v?           GetOperation eID, count, op C)&gL=O*$           If op.Type="ShiftZ" Then ((RpT0rP\               DeleteOperation eID,count YWcui+4p}               count=count-1 ,z0~mN           End If 1eE]4Z4Q           count=count+1 Y-neD?VN       Wend ,{`o/F/   X_0{*!v8       'Set new z-shift &|'Kut?8       op.Type = "ShiftZ" 8M3p\}O       op.val1 = tlens a!^-~pH:       op.parent = parID :r vO8.\       AddOperation eID, op T_(e(5       Print "Set lens thickness = " & tlens Fu1|b2B-x   \0*yxSg,^       '************************************************************************* )'K!)?&d       'Lens index of refraction k<j)?_=`       '************************************************************************* -Iruua7b       eID = FindMaterial( "Lens" ) Q8gdI       GetModelMaterial eID, mat VxPTh\O*[   8eS@<[[F#       mat.Nd = nlens W"}*Q-8W       SetModelMaterial eID, mat bb O;AiHD       Print "Set lens index of refraction = " & nlens 7#*CWh1BNO   (:k`wh &       '************************************************************************* h0QQP       'Pupil diameter FOyfk$       '************************************************************************* aVL%-Il}       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) D4S?bZFHo   T1 .@Tbbt       'Adjust pupil diameter (trimming volume inner hole) bv"({:x   .tZ$a_O       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" !Bbwl-e`   f3|=T8"t       ' Adjust pupil location to just in front of the lens {%}6d~Bg       parID = FindFullName( "Geometry.Arizona Eye" ) I9&<:`       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) iJ#oI@s       count = 0 {]N?DmF       While GetOperationCount(eID)>count $)a5;--W           GetOperation eID, count, op vv_?ip:t           If op.Type="ShiftZ" Then \zDV|n~{w               DeleteOperation eID,count ~&|i'f[               count=count-1 +@v} (           End If AMfu|%ZL           count=count+1 82l";;n4p       Wend v)pWx0l=       op.Type = "ShiftZ" 1#RA+d(       op.val1 = taq-0.01 6%axbB       op.parent = parID ?E+XD'~       AddOperation eID, op ee\zU~   K",]_+b       Print "Set pupil diameter = " & pupilDiam j* ja)   ai2}vR       'Update AZ Eye subassembly Description (acRYv(       eID = FindFullName( "Geometry.Arizona Eye" ) 0']M,iC/       GetEntity eID, entity %"B$I>h       entity.Description = "Accommodation = " & A & "D" {(Z1Jo Sl       SetEntity eID, entity y[eNM6p   ovVU%2o1b       Update yU`IyaazZ       Print "DONE!" 3F3?be        0$ EJ4   End Sub 4K% YS   GQ8P}McA   如果屈光度是4，光瞳直径是4，则会输出如下数据： QY!A[!6h   ;W:Q}[   Accommodation = 4 Diopters 7MfvU|D[d/   Pupil Diameter = 4 mm Vt>E\{@[t   Set aqueous humor thickness = 2.81 #SOe&W5   Set anterior lens radius = 10.4 and conic constant = -2.375869 g9.hR8X   Set posterior lens radius = -4.424557 and conic constant = -3.081019 %M:"Ai5:   Set lens thickness = 3.927 v<**GW]neD   Set lens index of refraction = 1.42672 rkp0ej2-   Set pupil diameter = 4 N9Vcp~;   DONE!

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