Arizona眼睛模型

EbQa?   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。 %D=]ZV](   9pSUIl9|j   模型 G}zZQy   tkKJh !Q7   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。 H)(jh   Table 1. AZ眼睛模型的定义 p( LZ)7/   }JgYCsF/f   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. L^`}J7r   ,xi({{L*   光源 ]uh3R{a/   b/("Y.r=   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。 [k%4eO2p"   6,b"   图1. 光源和提示信息使用 dA~ 3>f*b_   2I'~2o   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。 YwDt.6(+,    #ToK$8   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 !36]ud&   图2. 字母F光源的设定方法光 Y3U9:VB   V"KS[>>f   图3. 字母F在视网膜上位置点列图 PAF8Wlg   ^A_;#vK   视网膜的散射 SZU \i*   5FeFN)   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 t+Bf#:   mI1H!   图4. 视网膜朗伯散射设定 Jh/ E@}'    #1nJ(-D+   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 I:j3sy   (R}ii} &   图5. 视网膜重点采样规格设定 ef"?|sn   Gu0 ,)jy\   脚本 Vm1-C<V9   cntco@   内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： Li{~=S@N*   图6. 用户对话框的创建与编辑 2@j"; +   图7. 用户对话框编辑器 @z`@f"l   R W/z1   如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 va)%et0!   余下的脚本计算与屈光度有关的所有参数。 N@T.T=r   N_C;&hJN$w   分析 @* ust>7   es:2M |#O   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 RVw9Y*]b   图7. 字母F在视网膜上颜色分析 ;3'N Mk   uZjC c M   脚本代码  vb{i   \%jVg\4'   Option Explicit     'Remove this to enable non-dimensioned variables to be used. :Ixx<9c.   #;KsJb)N.   Dim entity As T_ENTITY ._Zt=jB   Dim op As T_OPERATION {tP%epQ   Dim mat As T_MODELMATERIAL _"a=8a06G   Dim A As Double )u:Q) %$t   Dim pupilDiam As Double 'I}:!Z   Dim eID As Long ]3{0J   Dim parID As Long <cN~jv-w$   Dim count As Integer v6(E3)J7   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double +~zXDBS9   Dim tlens As Double, nlens As Double sN=6gCau   Dim curv As Double, conic As Double F"+o@9]   Dim ok As Long L:nXWz   gxNL_(A   Sub Main z,SYw &S   <i\A_qqc/       '用户输入对话框 _o3e]{       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 W~n.Xeu{C           TextBox 220,21,40,21,.TextBox1 'default: 0 R[tC^]ai           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 [IZM.r`Z           OKButton 40,91,90,21 ~"x5U{K48S           CancelButton 190,91,90,21 q<vf,D@{ !           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Y,S\2or$           TextBox 220,49,40,21,.TextBox2 'default: 4 h!@,8y[B       End Dialog Tb;d.^       Dim dlg As UserDialog 5f'DoT   `TqSQg_l       ok = Dialog (dlg) koG{ |elgB   ;r\(p|e       If ok=0 Then    'cancel button was pressed sUkm|K`#           Print "Execution cancelled." :;;E<74e i           End ;zTuKex~       End If AEirj /   SUCUP<G       'Assign accommodation and pupil diameter & use defaults if field left empty eP1nUy=T       If dlg.TextBox1 = "" Then F?+3%>/A@           A = 0           'Default accommodation sfT+i;p       Else 0rSIfYZa           A = CDbl(dlg.TextBox1) ;E;To\NCYF       End If q}|U4MJm   ,V] ]:eR       If dlg.TextBox2 = "" Then Pf_F59"           pupilDiam = 4   'Default pupil diameter 6(&Y(/       Else Lz9#A.           pupilDiam = CDbl(dlg.TextBox2) G`h+l<       End If Z [Xa%~5>5   zR6siAV9       Print " " lU]un&[N       Print "Accommodation = " & A & " Diopters" jF"YTr6       Print "Pupil Diameter = " & pupilDiam & " mm" @~ Dh'w2q   GV|9H]_,I       ' Calculate new parameters with accommodation 8ip7^       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 9-1#( Y6S   8kL4~(hY       Rant = 12.0 - 0.4*A                     'Radius of anterior lens 0BPMmk       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 7v}x?I   q z&+=d@       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens .9G<y 4       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens !cW[G/W8   v5ur&egVs       tlens = 3.767 + 0.04*A                  'Lens thickness /TQ}} YVw   zoDZZ%{       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction #G]!%   z2c5m       'Adjust parameters to account for accommodation -4#2/GXNO   b;mSQ4+       '************************************************************************* '(+<UpG_Q}       'Aqueous thickness (Position of Lens) ^4Am %yyT       '************************************************************************* a~LC+8|JW       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) qOV[TP,       GetCustomElement eID, entity ~ AQp|   &N ZfJs       parID = FindFullName( "Geometry.Arizona Eye" ) ;$j7H&UNQj   H5>hx{       ' Delete any shift(s) in z w)]H ^6       count = 0 {04"LAE       While GetOperationCount(eID)>count uwIc963           GetOperation eID, count, op V,v[y\           If op.Type="ShiftZ" Then #.B"q:CW*P               DeleteOperation eID,count XEM'}+d               count=count-1 \kamcA           End If &<'n^n           count=count+1 qk(P>q8[       Wend ?NNn:tiD   ~:Uwg+]j       'Set new shift in (WlIwKP       op.Type = "ShiftZ" V:NI4dv/R       op.val1 = taq #%3rTU       op.parent = parID -ZOBAG*       AddOperation eID, op hv$yV%.`       Print "Set aqueous humor thickness = " & taq-0.55 YA(@5CZ   #<7O08:       '************************************************************************* xvLn'8H.       'Radius and conic constant of anterior lens m(OvD!       '************************************************************************* >?W[PQ5yx       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) %~|HFYd       GetConic eID, entity, curv, conic ) iQ    [f~N_G6I^o       SetConic eID, entity, 1/Rant, CCant `Kl`VP=c       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant =TvzS%U   #b0{#^S:       '************************************************************************* ?ne _m:J[       'Radius and conic constant of posterior lens !hxIlVd {       '************************************************************************* %!Q`e79g8       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) \g)Xt?w0Wo       GetConic eID, entity, curv, conic !7B\Xl'S   ?|;yVew       SetConic eID, entity, 1/Rpost, CCpost "v*8_El       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 0\{BWNK   w]j+9-._       '************************************************************************* >ndJNinV       'Lens thickness (Position of posterior lens surface) ?`?T7w|3 y       '************************************************************************* wgeNs9L   vW,snxK6y&       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) l?E a#   ~89P[ $6       ' Delete any z-shift(s) gW(gJ; L,%       count = 0 |tMn={       While GetOperationCount(eID)>count JwnAW}=           GetOperation eID, count, op J<j&;:IRd           If op.Type="ShiftZ" Then 7iC *Pr               DeleteOperation eID,count [V#r7a               count=count-1 ("7M b{           End If r4_eTrC,           count=count+1 )n7l'}o?+       Wend u9-nt}hGYM   z;u> Yz+3       'Set new z-shift DLE8+NV8        op.Type = "ShiftZ" [^H"FA[       op.val1 = tlens L7Dh(y=;7       op.parent = parID "HMP$)d       AddOperation eID, op cRvvzX       Print "Set lens thickness = " & tlens D6D1S/:ij'   4NEq$t$Jn       '************************************************************************* gA#RM5x@       'Lens index of refraction {WN(&eax       '************************************************************************* 6V9doP]i       eID = FindMaterial( "Lens" ) R_P}~l       GetModelMaterial eID, mat Tz&Y]#h_   &6 -k#r       mat.Nd = nlens GDaN       SetModelMaterial eID, mat }H:F< z*       Print "Set lens index of refraction = " & nlens C @y8.#l   sf}Dh       '************************************************************************* ajhEL?%D       'Pupil diameter >r5P3G1       '************************************************************************* mbl]>JsQD       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) s,VXc/   &tR(n$M@>       'Adjust pupil diameter (trimming volume inner hole) D,l,`jv*   ]6Ug>>x5       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" pI+!92Z   v'2[[u{7*       ' Adjust pupil location to just in front of the lens |C \}P       parID = FindFullName( "Geometry.Arizona Eye" ) BI[JATZG       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) AT Zhr. H       count = 0 co4h*?q       While GetOperationCount(eID)>count vEM(bT=H           GetOperation eID, count, op wJb# g0           If op.Type="ShiftZ" Then ewNz%_2               DeleteOperation eID,count bte~c               count=count-1 x LBQ           End If 1&=0Wg0ig           count=count+1 mwv( j_       Wend oj,lz?       op.Type = "ShiftZ" <<A`aU^fX       op.val1 = taq-0.01 2],_^XBvB       op.parent = parID <3PL@orO       AddOperation eID, op X8eJ4%   oz'\q0       Print "Set pupil diameter = " & pupilDiam FUK3)lT   ~%u|[$       'Update AZ Eye subassembly Description 6~:Sgt nU       eID = FindFullName( "Geometry.Arizona Eye" ) n@C~ev@%S       GetEntity eID, entity rI$`9d       entity.Description = "Accommodation = " & A & "D" :yT-9Ze%q       SetEntity eID, entity 6!iJ;1PeE   aFiCZHohw       Update {MAQ/5       Print "DONE!" NBh%:tu7M        TfxwVPX   End Sub !;@_VWR   h<l1]h+x   如果屈光度是4，光瞳直径是4，则会输出如下数据： `+lHeLz':   <<9Va.   Accommodation = 4 Diopters RIM`omM   Pupil Diameter = 4 mm ? ]sM8Bd}   Set aqueous humor thickness = 2.81 ,[p T4G   Set anterior lens radius = 10.4 and conic constant = -2.375869 R`Aj|C z   Set posterior lens radius = -4.424557 and conic constant = -3.081019 sGDV]~E   Set lens thickness = 3.927 #0I{.Wy]   Set lens index of refraction = 1.42672 fHrt+_Zn|   Set pupil diameter = 4 D;GD<zC]   DONE!

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