Arizona眼睛模型

pJV<#<#Z   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。 9Y0w SOSW   Qax=_[r   模型 9OX&;O+5   v&|o5om   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。 `Os@/S   Table 1. AZ眼睛模型的定义 @<h@d_8^k   ,XR1N$LN8_   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. x2l~aw#?   *M09Y'5]   光源 GP1b/n3F1   h(ZZ7(ue   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。 "HlT-0F   a:C ly9   图1. 光源和提示信息使用 $vx]\` ^   uq'T: d   除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 V TS8IXz   ]e!9{\X,*   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 W w:,O48%   图2. 字母F光源的设定方法光 } qxwNmx   CnN PziB   图3. 字母F在视网膜上位置点列图 n{aD4&   kyMWO*>|   视网膜的散射 p4[cPt~C   U8 '}(   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 r761vtC#   wMr*D['" #   图4. 视网膜朗伯散射设定 s>ilxLSX]   cJ=0zEv   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 c3lU   DY1UP(y   图5. 视网膜重点采样规格设定 s9X?tWuL   FbhF45H   脚本 ?`8jn$W^   HW"@~-\   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： d[=~-[   图6. 用户对话框的创建与编辑 B^nE^"b   图7. 用户对话框编辑器 P9c!   ?cF`T/z]"   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。 o!bV;]   余下的脚本计算与屈光度有关的所有参数。 ;<hLy(@   sN"<baZ   分析 OlI|.~   Qq+$ea?>   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 B:;$5PUTc   图7. 字母F在视网膜上颜色分析 bi~1d"j   7Ji|x{``   脚本代码 Xs}.7   =#0f4z   Option Explicit     'Remove this to enable non-dimensioned variables to be used. u0p[ltJ,   ^ZP $(a4   Dim entity As T_ENTITY #q?'<''d,   Dim op As T_OPERATION ?h\fwF3   Dim mat As T_MODELMATERIAL y rH@:D/   Dim A As Double &PZ&'N|P   Dim pupilDiam As Double $\Oc]%   Dim eID As Long /0CS2mLC   Dim parID As Long 17la/7l<   Dim count As Integer $Y`oqw?g+^   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 2fN2!OT   Dim tlens As Double, nlens As Double #|8Ia:=s   Dim curv As Double, conic As Double %>Q[j`9y   Dim ok As Long Opavno%&   < #FxI   Sub Main z;iNfs0i$   ]sLdz^E3D       '用户输入对话框 Uhs/F:E[A       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 _59f.FsVR           TextBox 220,21,40,21,.TextBox1 'default: 0 "rA-u)Te           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 g|TWoRx:           OKButton 40,91,90,21 /:B2-4>Q!           CancelButton 190,91,90,21 R`KlG/Tk           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 L _D#           TextBox 220,49,40,21,.TextBox2 'default: 4 cY]BtJ#       End Dialog  Z2a~1BL       Dim dlg As UserDialog FRhHp(0}5   3FY87R        ok = Dialog (dlg) 9x`1VR :   k@Qd:I;;       If ok=0 Then    'cancel button was pressed L9{y1'')           Print "Execution cancelled." B_mT[)ut           End OMfw#       End If 56o(gCj?y   *47HN7       'Assign accommodation and pupil diameter & use defaults if field left empty 'C7$,H'       If dlg.TextBox1 = "" Then P](/5KrK           A = 0           'Default accommodation l=UXikx       Else <P~pn!F}           A = CDbl(dlg.TextBox1) Tm\a%Z`U>       End If [[#zB-|   S ^]mF>xX8       If dlg.TextBox2 = "" Then (&MtK1; ;           pupilDiam = 4   'Default pupil diameter E5qt~:C|       Else xL [3R            pupilDiam = CDbl(dlg.TextBox2) i&^]qL|J       End If ~^bf1W[   fG zx;<0P!       Print " " !?)aZ |r       Print "Accommodation = " & A & " Diopters" E(F?o.b       Print "Pupil Diameter = " & pupilDiam & " mm" zJ)`snN|   +;T\:'CU       ' Calculate new parameters with accommodation hx!:F"#       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ;;S9kNp^v   V3Ep&<=/       Rant = 12.0 - 0.4*A                     'Radius of anterior lens '>cZ7:       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens MzMVs3w|   n"w>Y)C(X)       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens "m>BE       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens (QTQxZ   l6- n{ zG       tlens = 3.767 + 0.04*A                  'Lens thickness ~p?D [] h   3/y"kl:<-       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction %/2OP &1<   O"}O~lZ[6T       'Adjust parameters to account for accommodation WCY5F   Th X6e       '************************************************************************* SohNk9u[8       'Aqueous thickness (Position of Lens) [>LO'}%       '************************************************************************* JFdMYb       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) @6M>x=n5       GetCustomElement eID, entity ]?T,J+S   rgo!t028^       parID = FindFullName( "Geometry.Arizona Eye" ) 87F]a3   +~EnrrT+W       ' Delete any shift(s) in z c*r@QmB:       count = 0 r6&+pSA>       While GetOperationCount(eID)>count %%9T-+T           GetOperation eID, count, op H2'djZ           If op.Type="ShiftZ" Then Y() ZM               DeleteOperation eID,count =zR9^k               count=count-1 W/VEB3P>Z           End If liBFx6\"S           count=count+1 GL _hRu       Wend wlQ @3RN>   85q!FpuH       'Set new shift in Y.q$"lm7k       op.Type = "ShiftZ" !$/P8T``M       op.val1 = taq xt6%[)       op.parent = parID v%kl*K`*       AddOperation eID, op e5D\m g)       Print "Set aqueous humor thickness = " & taq-0.55 Tv `&   1)5/a5       '************************************************************************* H vHy{S4       'Radius and conic constant of anterior lens ZFtJoGaR       '************************************************************************* WD5jO9Oai       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) (Vn3g ra       GetConic eID, entity, curv, conic H6Ytp^~>   Nxt`5kSx=       SetConic eID, entity, 1/Rant, CCant "MD6<H       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant wb%4f6i   e0]#vqdO       '************************************************************************* xf?"Q#       'Radius and conic constant of posterior lens .$1S-+(kV       '************************************************************************* b81cq,       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ;X:Bh8tEV       GetConic eID, entity, curv, conic Vh^ :.y   t qUBl?i       SetConic eID, entity, 1/Rpost, CCpost 2Sk hBb=d       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost vs>Pd |p;   Ffd4c       '************************************************************************* 7q:;3;"9       'Lens thickness (Position of posterior lens surface) pU<GI@gU       '************************************************************************* P`S'F_I N   L3\(<[       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) B`w8d[cL7   M,cz7,       ' Delete any z-shift(s) ;Aheeq746       count = 0 R B6TM       While GetOperationCount(eID)>count 2Ima15^+F           GetOperation eID, count, op L8oqlq( 9           If op.Type="ShiftZ" Then wv=U[:Y               DeleteOperation eID,count .J=QWfqt               count=count-1 F0"("4h:           End If rHqP[[4B'           count=count+1 ftQ;$@       Wend TW wE3{iF   'e6J&X       'Set new z-shift 0X$2~jV>       op.Type = "ShiftZ" #ApmJLeCO       op.val1 = tlens b&]z^_m)       op.parent = parID :;IZ|hU       AddOperation eID, op +U>Y.YP       Print "Set lens thickness = " & tlens 1/syzHjbY   FbH@qHSH       '************************************************************************* 2IP<6l8N       'Lens index of refraction zn0%%x+!g       '************************************************************************* ?0-3J )kW       eID = FindMaterial( "Lens" ) I,aaSBwt&2       GetModelMaterial eID, mat y-S23B (   mE'HRv       mat.Nd = nlens tOZ-]>U       SetModelMaterial eID, mat IsVR4t]       Print "Set lens index of refraction = " & nlens _,? xc"   -FrK'!\       '************************************************************************* 4QYStDFe       'Pupil diameter ZkdSgc')       '************************************************************************* /(9.Fqe(       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) k^#*x2b    Y=H_U$       'Adjust pupil diameter (trimming volume inner hole) |oQhtk8.   9JeT1\VvHY       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" b?2 \j}   p9!jM\(       ' Adjust pupil location to just in front of the lens |x=(}g       parID = FindFullName( "Geometry.Arizona Eye" ) ]ki) (Bb       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) [#AI!-       count = 0 dz/3=0       While GetOperationCount(eID)>count fP- =wd           GetOperation eID, count, op H`yUSB IP           If op.Type="ShiftZ" Then _bv9/#tR               DeleteOperation eID,count F^lau f               count=count-1 x]608I T           End If 0IHAoV60           count=count+1 <p?oFD_e4       Wend HcV,r,>e       op.Type = "ShiftZ" 0d89>UB-8q       op.val1 = taq-0.01 kX*.BZI}C       op.parent = parID mi@uX@ #       AddOperation eID, op + x?8\   dsK*YY jH       Print "Set pupil diameter = " & pupilDiam mZ0_^   QVmJ_WT       'Update AZ Eye subassembly Description CUft       eID = FindFullName( "Geometry.Arizona Eye" ) ?5EMDawt       GetEntity eID, entity YpG6p0 nd       entity.Description = "Accommodation = " & A & "D" BFqM6_/J       SetEntity eID, entity DZ:$p.   DweF8c       Update %][zn$aa|       Print "DONE!" dV^ck+        f'tQLF[r<   End Sub j# l1KO^y   c'Q.2^w^   如果屈光度是4，光瞳直径是4，则会输出如下数据： $dK o}   ^a|   Accommodation = 4 Diopters :>jzL8   Pupil Diameter = 4 mm P` Gb}]rW   Set aqueous humor thickness = 2.81 KB{/L5   Set anterior lens radius = 10.4 and conic constant = -2.375869 ZfS"   Set posterior lens radius = -4.424557 and conic constant = -3.081019 M{=p0?X   Set lens thickness = 3.927  ,0i72J   Set lens index of refraction = 1.42672 <AHdz/N   Set pupil diameter = 4 qy-Hv6oof   DONE!

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