Arizona眼睛模型

ckPI^0A!   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。 o]|a5.O   : ]oRx   模型 o`]u&   @(H   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。 Qs.g%   Table 1. AZ眼睛模型的定义 zg83->[   &r Lg/UEV-   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. *eo<5YUHt   B!cg)Y?.bd   光源 uM<6][^`   =+j>?Yi   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。 ZNvnVW<   DIurFDQSS   图1. 光源和提示信息使用 jTJ]: EN   .<C}/Cl   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。 h[0,/`qb{   BI,j/SRK   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。 $Z;?d@6yI   图2. 字母F光源的设定方法光 &S"o jbb   er?'o1M   图3. 字母F在视网膜上位置点列图 &k+'TcWm   $6XCHVx   视网膜的散射 zp2IpYQ,3   .i B?:   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 @]H:=Q'gj   tGs=08`   图4. 视网膜朗伯散射设定 `"<} B"s   {{?[b^   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 {1y-*@yU(   ^rc!X]C9   图5. 视网膜重点采样规格设定 uYPdmrPB?l   1Yy5bg6+E   脚本 5]&vs!wH   qdB@P   内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： O0{M3-   图6. 用户对话框的创建与编辑 P!{ O<P   图7. 用户对话框编辑器 /2&jId   %jK-}0Tu   如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 P{eL;^I   余下的脚本计算与屈光度有关的所有参数。 ,?+rM ;   XQu~/{A=   分析 f.`noZN   qF{u+Ms   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 AWP CJmr   图7. 字母F在视网膜上颜色分析 p AzPi   n:GK0wu.s   脚本代码 9IKFrCO9,   )jK"\'cK   Option Explicit     'Remove this to enable non-dimensioned variables to be used. *sqq]uD   Nt^R~#8hF>   Dim entity As T_ENTITY bGvALz'   Dim op As T_OPERATION 9&=~_,wJd   Dim mat As T_MODELMATERIAL b:Lp`8Du   Dim A As Double  t]Xdzy   Dim pupilDiam As Double 5uK:f\y)l   Dim eID As Long e`#c[lbAAM   Dim parID As Long n\}!'>d'   Dim count As Integer |\j'Z0   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double SLL%XF~/Sb   Dim tlens As Double, nlens As Double L{|V13?   Dim curv As Double, conic As Double >_1*/o JO   Dim ok As Long (z0S5#g ,x   0+0 +%#?   Sub Main DKCPi0   #]i*u1       '用户输入对话框 q&Sd+y&       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 0(;d<u)fS           TextBox 220,21,40,21,.TextBox1 'default: 0 Us'm9 J           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Vh:%e24Z           OKButton 40,91,90,21 xT I&X9P           CancelButton 190,91,90,21 ]&1Kz 2/           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 @X_x?N           TextBox 220,49,40,21,.TextBox2 'default: 4 T^8t<S@`       End Dialog <8[BB7       Dim dlg As UserDialog nZa.3/7dJ   ^c}Z$V       ok = Dialog (dlg) `'[u%UE   F_=RY]       If ok=0 Then    'cancel button was pressed +qe!KPk2           Print "Execution cancelled." yc2c{<Ya5           End l;: L0(('       End If 8/*q#j   ]lzt"[       'Assign accommodation and pupil diameter & use defaults if field left empty |k:MXI       If dlg.TextBox1 = "" Then @CU3V+           A = 0           'Default accommodation aEVBU       Else _e$15qW+           A = CDbl(dlg.TextBox1) KFdTw{GlJ7       End If Qwb=N   nnX,_5s       If dlg.TextBox2 = "" Then v2:A 4Pd:+           pupilDiam = 4   'Default pupil diameter Tm5]M$)       Else j^T.7Zv           pupilDiam = CDbl(dlg.TextBox2) y]aV7 `]       End If &a% |L=FY   $*^Ms> Pa_       Print " " LY[XPV]t       Print "Accommodation = " & A & " Diopters" Rz1&(_Ps       Print "Pupil Diameter = " & pupilDiam & " mm" wQ qI@   W[[3'JTF       ' Calculate new parameters with accommodation Z:W6@j-~       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness W ~E%Eq3   G=!1P]M{       Rant = 12.0 - 0.4*A                     'Radius of anterior lens `uy)][j-       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 6wx;grt'Z   :}0y[qc3       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 9l9n T       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Vm6G5QwM   Tw"u{%t       tlens = 3.767 + 0.04*A                  'Lens thickness HDZB)'I   Y;d$x}dh       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction cdfJa   vFLQq,?Nh       'Adjust parameters to account for accommodation IlJ6&9   U7O~ch[,       '************************************************************************* x2/\%!mt       'Aqueous thickness (Position of Lens) An!1>`8r       '************************************************************************* RUUV"y       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) c1M/:*?%       GetCustomElement eID, entity fOCLN$x^   f4)fa yAVp       parID = FindFullName( "Geometry.Arizona Eye" ) ya3A^&:   H=[eO       ' Delete any shift(s) in z 9F)+p7VJq       count = 0 =.O8G=;DOA       While GetOperationCount(eID)>count m07= _4           GetOperation eID, count, op x zu)``?           If op.Type="ShiftZ" Then .'JO7of               DeleteOperation eID,count ms8de>A|H               count=count-1 yEyx.Mh.Af           End If Ahk6{uz           count=count+1 /"?yB$s       Wend }.ZX.qYX   yEIM58 l       'Set new shift in . dX ^3       op.Type = "ShiftZ" 9HrT>{@       op.val1 = taq /]m5HW(P7K       op.parent = parID o^FlQy\       AddOperation eID, op ~kPHf_B;z       Print "Set aqueous humor thickness = " & taq-0.55 $q,2VH:Ip   pA7&       '************************************************************************* >Q#h,x~vu       'Radius and conic constant of anterior lens RhR{EO       '************************************************************************* ?aOx b       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) <5(P4cm9       GetConic eID, entity, curv, conic |N, KA|Gdq   xR}^~14Bz       SetConic eID, entity, 1/Rant, CCant 9`       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant '4k l$I    #v+2W       '************************************************************************* 7pf]h$2       'Radius and conic constant of posterior lens K}7E;O5m"       '************************************************************************* RQhS]y@e       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Kab"r_'       GetConic eID, entity, curv, conic jez=q   TLbnG$VQS       SetConic eID, entity, 1/Rpost, CCpost oS3'q\       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost MJ"ug8N   6HocF/Ye       '************************************************************************* >dO1)       'Lens thickness (Position of posterior lens surface) T40&a(hXQ       '************************************************************************* U4;r.#qw,   :"QR;O@       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) MYNNeO   -Uj)6PzGu       ' Delete any z-shift(s) c"HB7       count = 0 -yyim;Nj       While GetOperationCount(eID)>count ,F}\njL           GetOperation eID, count, op F[am2[/<A           If op.Type="ShiftZ" Then Sd[%$)scC               DeleteOperation eID,count i2.g}pM.A               count=count-1 2OT RP4U           End If -u+@5K;^Y           count=count+1 jlaU3qXL       Wend i/U Dda"E   Z*uv~0a>9Q       'Set new z-shift h[eCi       op.Type = "ShiftZ" })#VO-J       op.val1 = tlens 8(d Hn       op.parent = parID 3XykIj1       AddOperation eID, op 5PF?Eq       Print "Set lens thickness = " & tlens rdj_3Utv   WXq=FZ-       '************************************************************************* 7Yv1et |       'Lens index of refraction YkWv*l       '************************************************************************* !fX&i6       eID = FindMaterial( "Lens" ) Oly"ll*K       GetModelMaterial eID, mat 287g 5    9t$#!2z       mat.Nd = nlens )ZZjuFQJ)       SetModelMaterial eID, mat }+mIP:T       Print "Set lens index of refraction = " & nlens XotiKCk|Aq   Q[PVkZ       '************************************************************************* vbA<=V*P       'Pupil diameter hHA!.u4&       '************************************************************************* xE>jlr?       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) "Yp:{e   |ty?Ah,vb       'Adjust pupil diameter (trimming volume inner hole) :zA/~/Wo   $G\WW@*GE       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" /$[9-G?   ;-0 d2Z       ' Adjust pupil location to just in front of the lens @n|Mr/PAj       parID = FindFullName( "Geometry.Arizona Eye" ) UY5wef2sF       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) r!+..c       count = 0 I3I1<}>]Z       While GetOperationCount(eID)>count X&LaAqlSG           GetOperation eID, count, op *;ehSg9           If op.Type="ShiftZ" Then SAVA6 64               DeleteOperation eID,count oMNt676               count=count-1 s!IX3rz           End If C(%b!Q,2           count=count+1 02$d       Wend %~e+H|       op.Type = "ShiftZ" r5,V-5b       op.val1 = taq-0.01 !eu\ShI       op.parent = parID &xWej2a!       AddOperation eID, op vZiuElxKi   s'4O]k`       Print "Set pupil diameter = " & pupilDiam $./&GOus   5FJ(x:k?z       'Update AZ Eye subassembly Description 1fH2obI~X       eID = FindFullName( "Geometry.Arizona Eye" ) 4j1$1C{       GetEntity eID, entity ROhhd.       entity.Description = "Accommodation = " & A & "D" 9 _oAs"w       SetEntity eID, entity $xU)t&Df   !kxJ&VmeF       Update |NdWx1       Print "DONE!" ~dBx<        eF"k"Ckt'   End Sub | LXVf   ('~}$%C   如果屈光度是4，光瞳直径是4，则会输出如下数据： 1j*E/L   n\i~H   Accommodation = 4 Diopters BROn2aSx%   Pupil Diameter = 4 mm eH_< <Xh!v   Set aqueous humor thickness = 2.81 }`pxs   Set anterior lens radius = 10.4 and conic constant = -2.375869 ID]E3K   Set posterior lens radius = -4.424557 and conic constant = -3.081019 I}sb0 Q&   Set lens thickness = 3.927 |yinVfZ0C   Set lens index of refraction = 1.42672 `N}aV Ns   Set pupil diameter = 4 im3BQIPR   DONE!

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