Arizona眼睛模型

!$!"$-5   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。 ,%]xT>kH   puK /;nns   模型 f/pr   fYzZW   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。 r(Y@;   Table 1. AZ眼睛模型的定义 y2@8?   %5/h;4    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. |c:xK{Ik   =~ ="#   光源 to3D#9Ep   4Dv42fO   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。 4fau 9bW   0[!38   图1. 光源和提示信息使用 3ms{gZbw   F}4jm,w   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。 CDGN}Q2_   |^t8ct?x~   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。 -MItZ   图2. 字母F光源的设定方法光 bS*oFm@u   h7[PU^m   图3. 字母F在视网膜上位置点列图 LE@`TPg$R   usOIbrQ   视网膜的散射 e]u3[ao   v1~`76^   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ;T?4=15c   aDE)Nf}   图4. 视网膜朗伯散射设定 Pt8 U0)i)   7VKTI:5y   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 hFr?84sAd   roE*8:Y   图5. 视网膜重点采样规格设定 uNG?`>4>   i>L>3]SRr{   脚本 ^n8r mh_%   3NC-)S    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： VH5Vg We   图6. 用户对话框的创建与编辑 yf7$m_$C'   图7. 用户对话框编辑器 ;c;PNihg   U#1,]a\   如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 "jEf$]   余下的脚本计算与屈光度有关的所有参数。 $.-\2;U   psZ #^@>mJ   分析 i;8tA!   >$p|W~x   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。  QKtTy>5   图7. 字母F在视网膜上颜色分析 [G[|auKF   KsBi<wY   脚本代码 ({#M*=&"   ZdY)&LJ   Option Explicit     'Remove this to enable non-dimensioned variables to be used. -VlXZj@u+   "=9kX`(1y   Dim entity As T_ENTITY 3erGTa[|q   Dim op As T_OPERATION V+2C!)f(   Dim mat As T_MODELMATERIAL sy;_%,}N   Dim A As Double QL_9a,R'r   Dim pupilDiam As Double enJgk(   Dim eID As Long "iY=1F"\R   Dim parID As Long BR [3i}Ud   Dim count As Integer b 6 B5   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double CDTM<0`%   Dim tlens As Double, nlens As Double 9akIu.H   Dim curv As Double, conic As Double /vLdm-4   Dim ok As Long q:/<^|   a@&P\"k   Sub Main d~U}IMj   zwa%$U       '用户输入对话框 $D)Ajd;       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 vMB`TpZ           TextBox 220,21,40,21,.TextBox1 'default: 0 eAD uk!Iq           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 EFNi# D8s           OKButton 40,91,90,21 V O= o)H\           CancelButton 190,91,90,21 mE}@}@(           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 d`+@ _)ea           TextBox 220,49,40,21,.TextBox2 'default: 4 UfWn\*J&k       End Dialog 1||\3 L/       Dim dlg As UserDialog lEe<!B$d"   wjeuZNYf       ok = Dialog (dlg) qu:nV"~_   8A ;)5!       If ok=0 Then    'cancel button was pressed M'D l_dx-           Print "Execution cancelled." 2)zAX"# /           End t+?m<h6w;l       End If :]hNw1e   NP#:} )       'Assign accommodation and pupil diameter & use defaults if field left empty jJK`+J,i}X       If dlg.TextBox1 = "" Then {5, ]7=]           A = 0           'Default accommodation }; ;Thfd       Else *VPjBzcH           A = CDbl(dlg.TextBox1) TC+ L\7        End If 2aR<xcSg   EDf"1b{PX       If dlg.TextBox2 = "" Then t/57LjV           pupilDiam = 4   'Default pupil diameter (:P-ef$]C       Else ^L@2%}6b`           pupilDiam = CDbl(dlg.TextBox2) ?8GggJC       End If v{[:7]b_=   4Lb!Au|Y       Print " " Jb (CH4|7       Print "Accommodation = " & A & " Diopters" W#.+C6/       Print "Pupil Diameter = " & pupilDiam & " mm" G)G 257K"~   ;qN;oSK       ' Calculate new parameters with accommodation [ PW\ l+i       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness x[_SNX"   c&GVIrJ       Rant = 12.0 - 0.4*A                     'Radius of anterior lens 1z5Oi u       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens s9)U",   #@3&1}J/       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens _/>JM0       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 9z$fDs}.q   &{uj3s&C        tlens = 3.767 + 0.04*A                  'Lens thickness <(c_[o/   o<8('j        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction .;$Ub[    TF1,7Qd       'Adjust parameters to account for accommodation S<Os\/*   {gkzo3       '************************************************************************* <9bfX 91       'Aqueous thickness (Position of Lens) PptVneujI       '************************************************************************* 5w+KIHhN|       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~9[O'       GetCustomElement eID, entity wr-/R"fX   =f/CBYNw@V       parID = FindFullName( "Geometry.Arizona Eye" ) 2t[P-on   4Y5lP00!}       ' Delete any shift(s) in z QHDR*tB:{       count = 0 !y\r.fm!A       While GetOperationCount(eID)>count /Bw <?:           GetOperation eID, count, op \5iMr[s           If op.Type="ShiftZ" Then {)jTq??               DeleteOperation eID,count :*} -,{uX               count=count-1 L~+/LV           End If S6CI+W           count=count+1 7M/v[dwL       Wend K2> CR$L   JyO2P       'Set new shift in _1,hO?TK       op.Type = "ShiftZ" ;p+[R+ )       op.val1 = taq bQ3txuha       op.parent = parID FMi:2.E       AddOperation eID, op C<Z{G%Qm       Print "Set aqueous humor thickness = " & taq-0.55 lHUd<kEC   S54q?sb_       '************************************************************************* QdrZi.qKH       'Radius and conic constant of anterior lens YSh@+AN       '************************************************************************* D"V(A\sZ       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) |z7V1xF       GetConic eID, entity, curv, conic jNvDE}'   oo\7\b#Jx       SetConic eID, entity, 1/Rant, CCant &,l(2z[       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant QR2S6 7-   E|vXM"zFl       '************************************************************************* )_YB8jUR-X       'Radius and conic constant of posterior lens D3B]       '************************************************************************* fDwK5?       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) r3B}d*v       GetConic eID, entity, curv, conic j sFfrS"*   Kh$Q9$       SetConic eID, entity, 1/Rpost, CCpost r~z'QG6v/       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost M#_|WL~   "<"m}rE?Q       '************************************************************************* |A/H*J,       'Lens thickness (Position of posterior lens surface) i\,I)S%yJ       '************************************************************************* B<Q)z5KK   H$+@O-       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4*ZY#7h   %tMx48'N       ' Delete any z-shift(s) 4[(NxXH8M       count = 0 &|<f|BMX       While GetOperationCount(eID)>count _%[po%]           GetOperation eID, count, op [j}JCmWY            If op.Type="ShiftZ" Then o1vK2V               DeleteOperation eID,count (3"N~\9m               count=count-1 s+? 2oPa           End If Xhq7)/jp           count=count+1 cNbUr       Wend /5<=m:   q3<kr<SP       'Set new z-shift :KgH 7s}       op.Type = "ShiftZ" o]Xt2E       op.val1 = tlens &s(J:P$!       op.parent = parID qJag>OY       AddOperation eID, op o{6q>Jm       Print "Set lens thickness = " & tlens m8=n`XI   zXM,cV/s       '************************************************************************* gW,hI>       'Lens index of refraction p#CjkL       '************************************************************************* 1~'jC8&J       eID = FindMaterial( "Lens" ) AN:yL a!       GetModelMaterial eID, mat @ 5^nrB   :\vs kk),       mat.Nd = nlens wk ^7/B       SetModelMaterial eID, mat R{fJ"Q5'       Print "Set lens index of refraction = " & nlens `sCn4-$8   hJ$9Hb       '************************************************************************* n m<?oI*\       'Pupil diameter gfs;?vP       '************************************************************************* Z,/K$;YWo       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ~_-]> SI   (c>g7d<>n       'Adjust pupil diameter (trimming volume inner hole) qa-FLUkIk!   NNF"si\FE       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" K Ax=C}9   ni&|;"Nt-       ' Adjust pupil location to just in front of the lens 0|RofL&o       parID = FindFullName( "Geometry.Arizona Eye" ) d)emTXB(       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 00.x*v       count = 0 ."H;bfcL_       While GetOperationCount(eID)>count QXZyiJX}           GetOperation eID, count, op 0muC4           If op.Type="ShiftZ" Then ~%8P0AP               DeleteOperation eID,count >Jmla~A               count=count-1 1!KROes4           End If F )(^c           count=count+1 X>Vc4n<}       Wend R7/S SuG6\       op.Type = "ShiftZ" vY-CXWC7       op.val1 = taq-0.01 u0h%4f!X       op.parent = parID ?id) 2V0s       AddOperation eID, op \y5lYb,*c_   l[Z o,4*       Print "Set pupil diameter = " & pupilDiam @QQ%09*   J(l\VvK       'Update AZ Eye subassembly Description c1"wS*u       eID = FindFullName( "Geometry.Arizona Eye" ) b2OwLt9       GetEntity eID, entity $Lr&V~       entity.Description = "Accommodation = " & A & "D" SvT0%2       SetEntity eID, entity 3uocAmY   ,7LfvZj4[       Update [zx|3wWAX-       Print "DONE!" >jX"         px<psR5   End Sub ryVYY>*(K   (N}-]%#   如果屈光度是4，光瞳直径是4，则会输出如下数据： oFj_o   ZC N}iQu4   Accommodation = 4 Diopters !fzS' pkk.   Pupil Diameter = 4 mm o]q~sJVk6   Set aqueous humor thickness = 2.81 *S ag   Set anterior lens radius = 10.4 and conic constant = -2.375869 )&@YRT\c?8   Set posterior lens radius = -4.424557 and conic constant = -3.081019 Hu"$)V   Set lens thickness = 3.927 gsbr8zwG,   Set lens index of refraction = 1.42672 gz~oQ l)zJ   Set pupil diameter = 4 2g= 6s   DONE!

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