Arizona眼睛模型

i90}Xyt   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。 1Gsw-a;a   {3hqp*xl   模型 N~;*bvW{   s=MT,   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。 >;)2NrJV   Table 1. AZ眼睛模型的定义 8;TAb.r    ]nUR;8   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. SD?BM-&~   wW-Ab   光源 i;c'P}[K   `gt:gx>a   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。 *zq.C   C\ vC?(n   图1. 光源和提示信息使用 W SQ[.C   U^[<   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。 :q^R `8;(t   pprejUR   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。 =p]mX)I_   图2. 字母F光源的设定方法光 {LP b))   IAf$]Fh   图3. 字母F在视网膜上位置点列图 AYcgi   id^|\hDR   视网膜的散射 &y7 0   .d~\Ysve   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。 e8,{|a   5SUN.%y   图4. 视网膜朗伯散射设定 il12T`a   _#!U"hkH   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。 "V4Q2T T   NPm;   图5. 视网膜重点采样规格设定 +{.780|   qe$33f*   脚本 `FZF2.N   ,h^r:g   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： R2rsJ   图6. 用户对话框的创建与编辑 II;Te7~   图7. 用户对话框编辑器 &~ *.CQa   rVH6QQF=\   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。 2ev*CX6.   余下的脚本计算与屈光度有关的所有参数。 '.(~   sw$2d   分析 }_}KV I   i@5)`<?   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 _ 5"+Dv   图7. 字母F在视网膜上颜色分析 X&a:g   +@ MPQv   脚本代码 ?^9BMQ+   S/4r\6   Option Explicit     'Remove this to enable non-dimensioned variables to be used. o5swH6Y.)J   8[zb{PRu   Dim entity As T_ENTITY W;zpt|kAH   Dim op As T_OPERATION S`m,S4-eD   Dim mat As T_MODELMATERIAL l!?yu]Yon   Dim A As Double *%!M4&   Dim pupilDiam As Double 6Ps. E   Dim eID As Long FI"HJwAs   Dim parID As Long 7 Wl-n   Dim count As Integer B+] D5K   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double I[0!SIqY   Dim tlens As Double, nlens As Double $DebXxJw0l   Dim curv As Double, conic As Double _c2WqQ-05   Dim ok As Long a460| w6   XF*.Jg]   Sub Main  $dQIs:   gEwd &J       '用户输入对话框 SV.z>p       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 WOX}Sw"           TextBox 220,21,40,21,.TextBox1 'default: 0 m#e*c[*G           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 `Ye8 Q5v"]           OKButton 40,91,90,21 :Q_3hK           CancelButton 190,91,90,21 y('k`>C           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 6w|J-{2           TextBox 220,49,40,21,.TextBox2 'default: 4 BRS#Fl:       End Dialog c_.-b=zm       Dim dlg As UserDialog IP3E9z_L   !GwL,)0@^       ok = Dialog (dlg) ]<XR]FHx)   ,LhCFw{8?~       If ok=0 Then    'cancel button was pressed sOBu7!G%           Print "Execution cancelled." 5Bjgr           End "OmD@ EMT       End If $s-Y%gc   9GU]l7C=z       'Assign accommodation and pupil diameter & use defaults if field left empty ;H'gT+t<c       If dlg.TextBox1 = "" Then %lw! e           A = 0           'Default accommodation ZnW@YC#9       Else W!T"m)S           A = CDbl(dlg.TextBox1) M.q=p[       End If d0'HDVd   # _i`#d)       If dlg.TextBox2 = "" Then !do?~$Og           pupilDiam = 4   'Default pupil diameter *\G)z|^yx       Else o0bM=njok           pupilDiam = CDbl(dlg.TextBox2) 1}%B%*N       End If 7zemr>sIh   @? c2)0       Print " " RY9V~8|M       Print "Accommodation = " & A & " Diopters" `aC){& AP(       Print "Pupil Diameter = " & pupilDiam & " mm" 5PT5#[   9X$ma/P[       ' Calculate new parameters with accommodation YW/QC'_iC       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness PcT?<HU   9(4&KZpK       Rant = 12.0 - 0.4*A                     'Radius of anterior lens u #w29Pm       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Az;t"   f+_h !j       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens #OO>rm$       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens g%[c<l9   t. ='/`!N       tlens = 3.767 + 0.04*A                  'Lens thickness *)M49a*UD   v59dh (:`Z       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ;r[@v347   T~0k"uTE       'Adjust parameters to account for accommodation }7E^ZZ]f   Vw||! d       '************************************************************************* @a:> $t       'Aqueous thickness (Position of Lens) Y_woKc*       '************************************************************************* 2;a(8^n       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) a`[uNgDO       GetCustomElement eID, entity %w7u]-tR   KGH/^!u+R       parID = FindFullName( "Geometry.Arizona Eye" ) aE;le{|!({   nw>8GivO       ' Delete any shift(s) in z u_(VEfs4       count = 0 J &pO%Q=b       While GetOperationCount(eID)>count SCvVt           GetOperation eID, count, op 8_<4-<}P:           If op.Type="ShiftZ" Then Y2o?gug               DeleteOperation eID,count p$Ox'A4               count=count-1 26&'X+n&           End If +_XzmjnDd           count=count+1 <Ln1pV~k       Wend pn.wud}R   )E@A0W       'Set new shift in <:SZAAoIV       op.Type = "ShiftZ"  #wL       op.val1 = taq C{gyj}5       op.parent = parID I!e})Y       AddOperation eID, op  A);       Print "Set aqueous humor thickness = " & taq-0.55 MrZh09y   fFb_J`'ue       '************************************************************************* 8"sb;        'Radius and conic constant of anterior lens z!l.:F       '************************************************************************* +qh[N@F       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) K+;e4_\       GetConic eID, entity, curv, conic Hemq+]6^   1pArZzm>       SetConic eID, entity, 1/Rant, CCant ='`/BY(m[       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant At-U2a#J{    IiY/(N+J       '************************************************************************* tjupJ*Rt       'Radius and conic constant of posterior lens J]nohICe       '************************************************************************* emCM\|NQg&       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ?>I;34 tL(       GetConic eID, entity, curv, conic ?VP8ycm   0g0i4IV       SetConic eID, entity, 1/Rpost, CCpost xlhG,bb7       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost vI>>\.ED   -r-k_6QP       '************************************************************************* W[Ls|<Q       'Lens thickness (Position of posterior lens surface) N<~t3/Nm       '************************************************************************* e" St_z(   O^oWG&Y;v       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) V5UF3'3;}   _f$^%?^       ' Delete any z-shift(s) <StN%2WQ1       count = 0 <1uZa       While GetOperationCount(eID)>count Zl^\Q=*s           GetOperation eID, count, op B}lvr-c#           If op.Type="ShiftZ" Then R}O_[               DeleteOperation eID,count *MKO I'               count=count-1 Qk: Y2mL           End If o,_?^'@           count=count+1  C uB`CI       Wend `aciXlqIF   59h)-^!       'Set new z-shift |y (Q       op.Type = "ShiftZ" |5lk9<z       op.val1 = tlens <g"{Wv: h       op.parent = parID e)d`pQ6       AddOperation eID, op &L=suDe       Print "Set lens thickness = " & tlens 17%Mw@+   nAv#?1cjz       '************************************************************************* \W~N       'Lens index of refraction ,J+}rPe"sf       '************************************************************************* Zy`m!]G]80       eID = FindMaterial( "Lens" ) <3LbNFP       GetModelMaterial eID, mat aA D^^l#   4K\G16'$v       mat.Nd = nlens ~E17L]ete       SetModelMaterial eID, mat EV]1ml k$       Print "Set lens index of refraction = " & nlens 4h|c<-`>t   5IE#\FITO|       '************************************************************************* G?O1>?4C       'Pupil diameter dYJ(!V&       '************************************************************************* EJMM9(DQ7       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) |fK1/<sz#   l9{hq/V       'Adjust pupil diameter (trimming volume inner hole) CsGx@\jN   La`NPY_:>       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" H#,W5EJzM   >qnko9V       ' Adjust pupil location to just in front of the lens 0X6YdW_2X       parID = FindFullName( "Geometry.Arizona Eye" ) ;U/&I3dzV       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Z^3rLCa       count = 0 >g1~CEMN#       While GetOperationCount(eID)>count :CG`t?N9M           GetOperation eID, count, op d,k!qjf=r           If op.Type="ShiftZ" Then V?6a8lJ               DeleteOperation eID,count gb[5&>(#               count=count-1 oH97=>           End If 3lrT3a3vV           count=count+1 'j#*6x D       Wend ~Y^+M*       op.Type = "ShiftZ" igCZ|Ru\       op.val1 = taq-0.01 ?WGA?J %2       op.parent = parID 'OITI TM       AddOperation eID, op 3dg1DR;   .s?L^Z^       Print "Set pupil diameter = " & pupilDiam &*M!lxDN   T<n       'Update AZ Eye subassembly Description X_q\Sg       eID = FindFullName( "Geometry.Arizona Eye" ) 6AAz       GetEntity eID, entity }|h# \$w       entity.Description = "Accommodation = " & A & "D" R`NYEptJ       SetEntity eID, entity X-b cQ@Oj   YL!P0o13r       Update ( nQ^       Print "DONE!" KI"#f$2&        Snj'y,p[   End Sub u|\1hLXX   g| o,uD   如果屈光度是4，光瞳直径是4，则会输出如下数据： Ouk^O}W6   zVViLUwG   Accommodation = 4 Diopters `+]Qz =}   Pupil Diameter = 4 mm ?>7[7(|   Set aqueous humor thickness = 2.81 ; 5*&xz   Set anterior lens radius = 10.4 and conic constant = -2.375869 Zu*F#s!tUI   Set posterior lens radius = -4.424557 and conic constant = -3.081019 "{A(x }'Y4   Set lens thickness = 3.927 yuh *   Set lens index of refraction = 1.42672 E^B'4   Set pupil diameter = 4 ?qb}?&1   DONE!

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