Arizona眼睛模型

q/d5P   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。 wB1-|=K1   Mc#O+'](f   模型 = C$@DNEc   110>p   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。 PpJE|[]   Table 1. AZ眼睛模型的定义 s= GOB"G   M&}oat*   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. 7YQK@lS   \gJapx(   光源 O3<Y_I^   @^XkU(m   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>A   V{AH\IV-   图1. 光源和提示信息使用 @gu77^='   XEgx#F ;F   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。 dc\u$'F@S   2EqsfU* I   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 ga2 Q3mV   图2. 字母F光源的设定方法光 U4^p({\|-   vxzf [   图3. 字母F在视网膜上位置点列图 %Zv(gI`A    n_xa)   视网膜的散射 Jegx[*O>b   K,L>    在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 5.C[)`_   Ck/_UY|   图4. 视网膜朗伯散射设定 LBbo.KxAe3   ?V\9,BTb)   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 bHWvKv+   ;+TF3av0zq   图5. 视网膜重点采样规格设定 @6i8RmOu}   tmY-m,U   脚本 )kY_"= d   Fl'xmz^   内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： dx?njR   图6. 用户对话框的创建与编辑 D?*sdm9r`   图7. 用户对话框编辑器 ~d#;r5>   VATXsD   如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 tE9_dR^K   余下的脚本计算与屈光度有关的所有参数。 4-}A'fTU8   ad3z]dUZ9   分析 .'NO~   C$..w80/1   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 bh;b` 5   图7. 字母F在视网膜上颜色分析 thm3JfQt   qY~$wVY(   脚本代码 )zL"r8si   (zTI)EV   Option Explicit     'Remove this to enable non-dimensioned variables to be used. /Y\E68_Fh   !>kv.`|7~   Dim entity As T_ENTITY ,0<F3h   Dim op As T_OPERATION :86luLFm   Dim mat As T_MODELMATERIAL VqO<+~M,E   Dim A As Double <cfH'~   Dim pupilDiam As Double j2{,1hj   Dim eID As Long }^Ua   Dim parID As Long Z\ gg<Q   Dim count As Integer J:-TINeB   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Q3'B$,3O^   Dim tlens As Double, nlens As Double RzY`^A6G6   Dim curv As Double, conic As Double 1KIq$lG{ E   Dim ok As Long z:Zn.e*$b   7s fuju(   Sub Main L};;o+5uJD   U37?P7i's       '用户输入对话框 #+ lq7HJ1       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 <11Tqb           TextBox 220,21,40,21,.TextBox1 'default: 0 ,,H$>r_;           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 T~~$= vP9           OKButton 40,91,90,21 vhquHy.qi#           CancelButton 190,91,90,21 []N$;~R7           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 `@.s!L(V           TextBox 220,49,40,21,.TextBox2 'default: 4 *ZSp9g"Z       End Dialog /%q9hI       Dim dlg As UserDialog !wb~A0m   ^(m6g&$(       ok = Dialog (dlg) 1q233QSW)   LX?r=_\       If ok=0 Then    'cancel button was pressed N5an9r&z(1           Print "Execution cancelled." \A\yuJ=           End UE#Ni 5       End If lbuW*)   5iI3u 7Mn1       'Assign accommodation and pupil diameter & use defaults if field left empty ):\{n8~       If dlg.TextBox1 = "" Then _kY[8e5           A = 0           'Default accommodation 674oL,       Else ch8w'           A = CDbl(dlg.TextBox1) 0|>       End If Qx,$)|_   3;l>x/amk       If dlg.TextBox2 = "" Then gWv+i/,           pupilDiam = 4   'Default pupil diameter \/4%[Q2QDm       Else tD0>(41K           pupilDiam = CDbl(dlg.TextBox2) oY6|h3T=Q$       End If E+c3KqM   |tJ%:`DGw       Print " " MJ/%$       Print "Accommodation = " & A & " Diopters" n]fbV/x       Print "Pupil Diameter = " & pupilDiam & " mm" /uz5V/i0   <w2NJ~M^       ' Calculate new parameters with accommodation 8\.1m9&r>o       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness `rdfROKv   898wZ{9       Rant = 12.0 - 0.4*A                     'Radius of anterior lens -hR\ Y2?       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens <^'+]?   I\%Lb z       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens )W6-h       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens @N_H]6z4   Qp. !U~       tlens = 3.767 + 0.04*A                  'Lens thickness 6F&]Mk]V8   |Ge/|;.v`       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction c@#zjJhW]   W#\}; P       'Adjust parameters to account for accommodation "XsY~   %+B-Z/1}       '************************************************************************* s]8J+8 <uO       'Aqueous thickness (Position of Lens) K/d&c]       '************************************************************************* cBF%])!       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) (Dh;=xG       GetCustomElement eID, entity E1ob+h:`d   7`<? fO       parID = FindFullName( "Geometry.Arizona Eye" ) S,9WMti4x   h:;eh       ' Delete any shift(s) in z wR+`("2{r       count = 0 V//q$/&8(       While GetOperationCount(eID)>count _v=WjN           GetOperation eID, count, op 9x^ /kAB           If op.Type="ShiftZ" Then :O+b 4R+               DeleteOperation eID,count m1o65FsY08               count=count-1 >8;%F<o2           End If x Bw.M{           count=count+1 Y9y*":&%       Wend fvMhq:Bu   I%C:d#p       'Set new shift in r_sl~^* :       op.Type = "ShiftZ" 0Ilvr]1a4       op.val1 = taq oqHm:u^2       op.parent = parID ;~$ $WU       AddOperation eID, op 78~V/L;@S2       Print "Set aqueous humor thickness = " & taq-0.55 pz}hh^]t   +9rbQ?'       '************************************************************************* ZLX`[       'Radius and conic constant of anterior lens KBH KcFk       '************************************************************************* f_2^PF>?       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) p)&\>        GetConic eID, entity, curv, conic QGG(I7{-   2#M:JgWV       SetConic eID, entity, 1/Rant, CCant K5rj!*x.o       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 8B+^vF    )^#Zg8L       '************************************************************************* 6Q.whV%y       'Radius and conic constant of posterior lens ?o5#Ve$-X       '************************************************************************* <KPx0g?=b       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Tm.w+@       GetConic eID, entity, curv, conic WREGRy   ms<uY Lp       SetConic eID, entity, 1/Rpost, CCpost Jd6Q9~z#       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ^F9zS`Yz2   #f;1f8yrN       '************************************************************************* n7.lF       'Lens thickness (Position of posterior lens surface)  Jiylrf`o       '************************************************************************* >Nl~"J|]q   l8us6       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) O[B_7   ,8?*U]}       ' Delete any z-shift(s) 1U9N8{xg9       count = 0 zb,`K*Z{       While GetOperationCount(eID)>count !O_^Rn+<2           GetOperation eID, count, op ~M1%,]           If op.Type="ShiftZ" Then ,?~,"IQyi[               DeleteOperation eID,count 8Kkr1}!wd               count=count-1 D ,^ U%<`           End If pvxqeC9`           count=count+1 {j*+:Gj0V       Wend *.Hnt\4|   58U[r)/       'Set new z-shift 8k'em/M~       op.Type = "ShiftZ" qqred>K       op.val1 = tlens "z4E|s       op.parent = parID iqP0=(^m       AddOperation eID, op W\Y 4%y}       Print "Set lens thickness = " & tlens b?L43t,   X]%4QIeS       '************************************************************************* m]pvJJ@       'Lens index of refraction uRhH_c-6C       '************************************************************************* |.nWy"L       eID = FindMaterial( "Lens" ) u)>*U'bM       GetModelMaterial eID, mat B%; +8]   0k]N%!U       mat.Nd = nlens |<icx8hbr       SetModelMaterial eID, mat -bQvJ`iF       Print "Set lens index of refraction = " & nlens 0_izTke   (I g *iJ%2       '************************************************************************* h0}-1kVT^       'Pupil diameter ( h,F{7       '************************************************************************* wj~8KHan       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 6 VDF@V$E   ]^%3Y       'Adjust pupil diameter (trimming volume inner hole) /tP   K*RRbtb       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Ut@)<N   n&&y\?n       ' Adjust pupil location to just in front of the lens P~>nlm82]       parID = FindFullName( "Geometry.Arizona Eye" ) +O6@)?pI       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) "<b84?V5       count = 0 m!if_Iq       While GetOperationCount(eID)>count !OemS7{           GetOperation eID, count, op N`fY%"5U>           If op.Type="ShiftZ" Then UQr+\ u               DeleteOperation eID,count 1-<Xi-=^{t               count=count-1 /m:}rD           End If VQ`O;n6/`           count=count+1 2V 'Tt3       Wend |3@ ]5f&       op.Type = "ShiftZ" _: x$"i       op.val1 = taq-0.01 =B2=UF       op.parent = parID ZrBxEf$f       AddOperation eID, op #k, kpL<a   b2H6}s"=w       Print "Set pupil diameter = " & pupilDiam 4 -W?u51"   ~o$=(EC       'Update AZ Eye subassembly Description cd#TKmh7re       eID = FindFullName( "Geometry.Arizona Eye" ) SNFz#*        GetEntity eID, entity Stpho4+/y       entity.Description = "Accommodation = " & A & "D" 7#QH4$@1P       SetEntity eID, entity c:5BQr '   f}4h}Cq       Update *z~Y*Q0       Print "DONE!" O;"%z*g.        I&0 yUhn   End Sub =?hlgQ   5E8PbV-l   如果屈光度是4，光瞳直径是4，则会输出如下数据： ^&%?Q_]   wAYc)u#   Accommodation = 4 Diopters zQJbZ=5Bu"   Pupil Diameter = 4 mm Qfi5fp=f   Set aqueous humor thickness = 2.81 oY: "nE   Set anterior lens radius = 10.4 and conic constant = -2.375869 7[\B{N9&W   Set posterior lens radius = -4.424557 and conic constant = -3.081019 @VAhmYz   Set lens thickness = 3.927 |v&&%>A2   Set lens index of refraction = 1.42672 xPv&(XZR   Set pupil diameter = 4 ),eiJblH   DONE!

]]4E)j8

umeb&\:8S-