Arizona眼睛模型

i8Y$cac!   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。 $4j$c|S!   14,Pf`5Sz   模型 9*lkx#   ~.,h12   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。 N1Pm4joH%   Table 1. AZ眼睛模型的定义 )f6:{ma   ]|y]?7   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. |y*-)t   xO< $xx   光源 E*F)jP,yo   OSsxO(;g   多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 nfV32D|3   l`}Ag8Q   图1. 光源和提示信息使用 cIIt ;q[   =b* Is,R/   除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 ydyGPZt   k'd(H5A   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 }}VB#   图2. 字母F光源的设定方法光 Lk-%I?   eyiGe1^C   图3. 字母F在视网膜上位置点列图 u VZouw#   W"@FRWcd   视网膜的散射 xq2 ,S   K[XFJ9   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 |=Mn~`9p   |4F3Gu   图4. 视网膜朗伯散射设定 DG&[.dR+   Jf,)Y>EI   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 !w[io;   ]-D;t~   图5. 视网膜重点采样规格设定 B:pIzCP   !QB(M@1   脚本 bS9<LQ*   P2+Z^J`Y>   内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： &!kr&g#]   图6. 用户对话框的创建与编辑 | Ts0h?"a   图7. 用户对话框编辑器 gDmwJr   Z!qHL$   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。 {[&_)AW6m%   余下的脚本计算与屈光度有关的所有参数。 / xfg4   BK_x5mGu3   分析 cN{-&\ 6L   *1Lkde@|{   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 ]/p)XH Ko   图7. 字母F在视网膜上颜色分析 'e3[m   ~\9bh6%R   脚本代码 NTHy!y<!h   |Q'l&Gt6   Option Explicit     'Remove this to enable non-dimensioned variables to be used. zLs[vg.(   3KF[ v{   Dim entity As T_ENTITY f&\v+'[p   Dim op As T_OPERATION -n-rKN.T   Dim mat As T_MODELMATERIAL Z]I[?$y   Dim A As Double 0wm z2zKV   Dim pupilDiam As Double l+>&-lX'   Dim eID As Long NY5?T0/[   Dim parID As Long 9Fl}"p[>L.   Dim count As Integer X:*Ut3"   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 6[h3pb/m   Dim tlens As Double, nlens As Double V8z91   Dim curv As Double, conic As Double y<G@7?   Dim ok As Long 1|L3} 2   rf%E+bh4   Sub Main :(,Eq?    ugM,wT&~Y       '用户输入对话框 g2=5IU<       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 (]|rxmycA           TextBox 220,21,40,21,.TextBox1 'default: 0 ?U:LAub           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 V4RtH           OKButton 40,91,90,21 2Et7o/\<           CancelButton 190,91,90,21 oJF@O:A           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 `};8           TextBox 220,49,40,21,.TextBox2 'default: 4 KfXE=v{t       End Dialog `hD\u@5Tw       Dim dlg As UserDialog |]5g+sd   ,3k"J4|d       ok = Dialog (dlg) *q8L$D   x,\PV>       If ok=0 Then    'cancel button was pressed 5-L?JD4&           Print "Execution cancelled." W9{>.E?           End YQ`GOP#/       End If ,6Kx1  c   eD0Rv0BV^       'Assign accommodation and pupil diameter & use defaults if field left empty OT_w<te       If dlg.TextBox1 = "" Then >Xq:?}-m2           A = 0           'Default accommodation :@TfhQV_=Q       Else Azrc+k           A = CDbl(dlg.TextBox1) &#'[]V%^F       End If Oj#nF@U   3*G7H       If dlg.TextBox2 = "" Then 3_Su5~^           pupilDiam = 4   'Default pupil diameter Q"UQv<       Else a G^k L           pupilDiam = CDbl(dlg.TextBox2) M"OXNPkc       End If m8F-#?~   mbBd3y       Print " " `Jh> 1l       Print "Accommodation = " & A & " Diopters" klG]PUzd       Print "Pupil Diameter = " & pupilDiam & " mm" )MFa~/x   Gw6*0&3')       ' Calculate new parameters with accommodation }LNpr       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Ed3 *fY   +I o[o6*       Rant = 12.0 - 0.4*A                     'Radius of anterior lens hlxZq       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens d,|W   odPq<'V|AY       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens NZ`( d       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens A]2zK?|s   Qo{Ez^q@J       tlens = 3.767 + 0.04*A                  'Lens thickness ?]}1FP   T<\Q4Coth       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction m'$]lf;*   O $uXQ.r       'Adjust parameters to account for accommodation ~S)o('   :qi"I;=6       '************************************************************************* i,BE]w       'Aqueous thickness (Position of Lens) 83UIH0(       '************************************************************************* NAjK0]SRY       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) zqg4@" p       GetCustomElement eID, entity d#.9!m~.   PNLtpixZ       parID = FindFullName( "Geometry.Arizona Eye" ) h_4o4#   xI}h{AF7       ' Delete any shift(s) in z }E+}\&       count = 0 /#M|)V*wn       While GetOperationCount(eID)>count fr8:L!9           GetOperation eID, count, op N<$U:!Z           If op.Type="ShiftZ" Then GMLq3_'               DeleteOperation eID,count h>w4{u0               count=count-1 dOArXp`s           End If R=~+-^O!           count=count+1 0[g8       Wend /GNLZm^   D^To:N7U       'Set new shift in KwOn<0P       op.Type = "ShiftZ" f{[U->#^       op.val1 = taq iCCY222:       op.parent = parID ~WK>+T,%       AddOperation eID, op s{#ZRmc2B       Print "Set aqueous humor thickness = " & taq-0.55 *Z=K9y,IC   5_b`QO       '************************************************************************* CF3Z`xD       'Radius and conic constant of anterior lens x|G#oG)_       '************************************************************************* Y9ueE+6       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) j"*ZS'0       GetConic eID, entity, curv, conic 7nB@U$]-Sz   `<2y [<y       SetConic eID, entity, 1/Rant, CCant '/kSUvd       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ~M%r.WFpA   >bWsUG9       '************************************************************************* k.>*!l0       'Radius and conic constant of posterior lens P]-d(N}/H       '************************************************************************* 1 ry:Z2       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) #P$=P2o       GetConic eID, entity, curv, conic ;=1]h&S   TjGe8L:       SetConic eID, entity, 1/Rpost, CCpost .asHFT7]9       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost MCU{@\?Xf   Lz2 AWqR       '************************************************************************* 9VdVom|e       'Lens thickness (Position of posterior lens surface) nC^?6il       '************************************************************************* 2`/ JT   KHKf+^uu       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) MjNCn&c   mV0F^5       ' Delete any z-shift(s) 6*Jd8Bva\o       count = 0 ,T?8??bZ       While GetOperationCount(eID)>count g![]R-$           GetOperation eID, count, op #>dfP"}&,           If op.Type="ShiftZ" Then 7yx Ze4~|#               DeleteOperation eID,count )e|Cd} 2               count=count-1 I{AteL           End If LF?83P,UJ#           count=count+1 T1c2J,+}R       Wend BL6t>   !1K<iz_8       'Set new z-shift T;X8T       op.Type = "ShiftZ" h"cLZM:6       op.val1 = tlens DbFTNoVR       op.parent = parID R:kNAtK       AddOperation eID, op /~V.qisZ       Print "Set lens thickness = " & tlens q}*"0r   Fy5xIRyI\F       '*************************************************************************  (-DA%       'Lens index of refraction 12v5*G[X       '************************************************************************* fg"@qE-;       eID = FindMaterial( "Lens" ) }2-<}m9}       GetModelMaterial eID, mat l j*ELy   dHc38zp       mat.Nd = nlens I^sWf3'db       SetModelMaterial eID, mat |\"vHt?@G       Print "Set lens index of refraction = " & nlens 3Vjuk7   $8h ^R#       '************************************************************************* +,<\LIP        'Pupil diameter t QkEJ pj       '************************************************************************* q3Re F_       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 4 F~e3   Ac!,#Fq       'Adjust pupil diameter (trimming volume inner hole) eYBo*   xiuAW       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 3UgusH3   @=q,,t$r       ' Adjust pupil location to just in front of the lens lob{{AB,!       parID = FindFullName( "Geometry.Arizona Eye" ) LyO,]       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) cy8+ @77       count = 0 #<|5<U       While GetOperationCount(eID)>count j$<uE{c           GetOperation eID, count, op 68?oV)fE           If op.Type="ShiftZ" Then PI ~LbDE               DeleteOperation eID,count 0o2o]{rM{2               count=count-1 GCCmUR9d           End If 8`}(N^=}           count=count+1 Tyt:Abym=       Wend 'jWd7w~(       op.Type = "ShiftZ" QIQ }ia       op.val1 = taq-0.01 }7YDe'5V       op.parent = parID e_s9E{(       AddOperation eID, op K}ACZT)Wp   6T{Zee       Print "Set pupil diameter = " & pupilDiam +N1oOcPC>C   4} uX[~e&       'Update AZ Eye subassembly Description f)hs>F       eID = FindFullName( "Geometry.Arizona Eye" ) {Buoo~       GetEntity eID, entity  ^! /7       entity.Description = "Accommodation = " & A & "D" aCzdYv\}&       SetEntity eID, entity c\~H_ ~F   }LQ*vD-Jj       Update 4qo4g+       Print "DONE!" e\i K        T5_z^7d   End Sub #+Z3!VS   ^Cb7R/R3   如果屈光度是4，光瞳直径是4，则会输出如下数据： 0/P!rH9   f2Frb   Accommodation = 4 Diopters P lJl#-BO   Pupil Diameter = 4 mm 2h0I1a,7   Set aqueous humor thickness = 2.81 oZ95)'L,   Set anterior lens radius = 10.4 and conic constant = -2.375869 |eL&hwqzG   Set posterior lens radius = -4.424557 and conic constant = -3.081019 6$[ 7t?u   Set lens thickness = 3.927 9],;i7c   Set lens index of refraction = 1.42672 mN3}wJ}J   Set pupil diameter = 4 x bF*4;^SI   DONE!

[o8a(oC

'8`{u[
: