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简介 0U !&|i\ 3S1{r
)[j 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。 ~%h&ELSw 1kD1$5 模型 T-]UAN"O ge1U1o 模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 Kw2]J)TO ENI|e,'[ Table 1. AZ眼睛模型的定义 WO6+r?0M2 在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 2wa'WEx umt`0m. : 光源 yZ]?-7 kh8 M= 多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 D={$l'y9p [ua[A;K 7%G&=8tq 图1. 光源和提示信息使用 H%Z;Yt8^gt 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。 BU7QK_zT: q29d= 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。 \FF|b"E_= f0YBy<a 图2. 字母F光源的设定方法光 0#ON}l)> #4!f/dWJp 图3. 字母F在视网膜上位置点列图 16Jjf|]j 视网膜的散射 mo,"3YW )@] W= 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。 Sy<io@df er2;1TW3E .- []po 图4. 视网膜朗伯散射设定 ?A~=.u@[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。 >FJK$>[1:p +n)bWB% SR`A]EC(V 图5. 视网膜重点采样规格设定 =LEzcq>XO 脚本 (`u+(M!^ 2sVDv@2 内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: >GzH_] 8#9OSupp 图6. 用户对话框的创建与编辑 t;:Yf 图7. 用户对话框编辑器 lE!.$L*k 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。 C4t~k 余下的脚本计算与屈光度有关的所有参数。 }=.C~f]A db}lN 分析 L`fT;2 nA%8
bZ+ 屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 Y&y<WN}Q t}MT<Jj 图7. 字母F在视网膜上颜色分析 B B^81{A 脚本代码 W)Y:2P<. )bpdj, Option Explicit 'Remove this to enable non-dimensioned variables to be used. J7~Kjl Q8]S6,pt Dim entity As T_ENTITY =#wE*6T9 Dim op As T_OPERATION v+dT7*^@ Dim mat As T_MODELMATERIAL 23opaX5V= Dim A As Double 5bsv05=e Dim pupilDiam As Double Tb*Q4:r" Dim eID As Long IxY!.d_s|~ Dim parID As Long A2Iqn5 Dim count As Integer . TNJuuO Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 3wfJ!z-E8 Dim tlens As Double, nlens As Double 8^R~qpg% Dim curv As Double, conic As Double n@S|^cH Dim ok As Long %6Y}0>gY D2io3Lo$ov Sub Main G {a;s-OA3 2%MS$Fto '用户输入对话框 MW=rX>tE Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 U;gy4rj TextBox 220,21,40,21,.TextBox1 'default: 0 HDz"i Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 SK_N|X]. OKButton 40,91,90,21 Qr?(2t# CancelButton 190,91,90,21 '%a:L^a? Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 aDE}'d1qo TextBox 220,49,40,21,.TextBox2 'default: 4 SW Hi iF@ End Dialog nrM-\' Dim dlg As UserDialog a!PN`N28 &@qB6!^ ok = Dialog (dlg) uFOYyrESc CZ(fP86e If ok=0 Then 'cancel button was pressed Tcq@Q$H Print "Execution cancelled." Cn>t"#zs!~ End xDmwiVy End If VxU{ZD~<Z" +.X3&|@k 'Assign accommodation and pupil diameter & use defaults if field left empty vnX~OVz2 If dlg.TextBox1 = "" Then mrlhj8W?! A = 0 'Default accommodation xJFxrG'c Else CR-2>,*a9 A = CDbl(dlg.TextBox1) }jg,[jw_"X End If \u 6/nvZ]N /)r[}C0 If dlg.TextBox2 = "" Then 5J3K3 pupilDiam = 4 'Default pupil diameter x0xQFlGk Else mEV@~){ pupilDiam = CDbl(dlg.TextBox2) WX$AOnEv End If QVD^p;b c2yZvi Print " " \Zn~y--Z Print "Accommodation = " & A & " Diopters" 3[%n@i4H| Print "Pupil Diameter = " & pupilDiam & " mm" <"LA70Hkk y"ms;w'z ' Calculate new parameters with accommodation |1/?>=dDm taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness O{=@c96rl ~B`H5# Rant = 12.0 - 0.4*A 'Radius of anterior lens Lx3`.F\mG CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens 7#9fcfL No]#RvEd3 Rpost = -5.224557 + 0.2*A 'Radius of posterior lens *(nu0 CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens CbT ;#0 <{.pYrn tlens = 3.767 + 0.04*A 'Lens thickness 4o( Q+6m L#/<y{ nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction TZ PUVOtL_ #LG<o3An 'Adjust parameters to account for accommodation A)nE+ec1 !GoHCe[10 '************************************************************************* KocNJ
TB 'Aqueous thickness (Position of Lens) w#;y '************************************************************************* GUsJF;;V eID = FindFullName( "Geometry.Arizona Eye.Lens" ) >7QC>ws% GetCustomElement eID, entity 7*47mJyc 6,skF^ parID = FindFullName( "Geometry.Arizona Eye" ) ,v(ikPzd
l/bZE.GJ ' Delete any shift(s) in z ,uS}wJAX count = 0 kT&GsR/ While GetOperationCount(eID)>count 2Vg+Aly4D GetOperation eID, count, op Q_|Lv& If op.Type="ShiftZ" Then u:\DqdlU` DeleteOperation eID,count ]DI%7kw' count=count-1
C0j`H( End If wUmcA~3D count=count+1 nsi&r Wend YHo*IX')C? 4J2C#Cs 'Set new shift in .OD{^Kq2 op.Type = "ShiftZ" =OooTZb:x- op.val1 = taq f >\~h,SLL op.parent = parID 1zY"Uxp AddOperation eID, op ,}$[;$ye Print "Set aqueous humor thickness = " & taq-0.55 }zHG]k,j lf2(h4[1R '************************************************************************* -2y>X`1Y 'Radius and conic constant of anterior lens Yfx'7gj '************************************************************************* Ert`
]s~ eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) P64<O5l/ GetConic eID, entity, curv, conic o1u?H4z &+8cI^kp SetConic eID, entity, 1/Rant, CCant ')j@OO3 Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Q E*`#r#e . AX6xc6
'************************************************************************* Na_O:\x# 'Radius and conic constant of posterior lens g}*F"k4j '************************************************************************* 7.C~ OrGR eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @Yh%.#\i% GetConic eID, entity, curv, conic 0%]F&| LW+^m6O SetConic eID, entity, 1/Rpost, CCpost ~.8p8\H Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost EY[J;H_b 7bx!A+, t '*************************************************************************
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ZZ 'Lens thickness (Position of posterior lens surface) A$o ?_ '************************************************************************* xX{gm'3UYa zgA/B{DaC; parID = FindFullName( "Geometry.Arizona Eye.Lens" ) =^gZJ@ F]^ZdJ2 ' Delete any z-shift(s) ?-9It|R count = 0 3X}>_tj While GetOperationCount(eID)>count M`.v/UQn GetOperation eID, count, op r7n-Xe If op.Type="ShiftZ" Then %jmL#IN) DeleteOperation eID,count I0C$ count=count-1 x)^t5"F End If 8hm|9 count=count+1 zX ?@[OT Wend ?DKwKt G,h=5y9_J 'Set new z-shift %P-z3 0FHp op.Type = "ShiftZ" eEMU,zCl op.val1 = tlens 0?8{q{ o+ op.parent = parID eh}{\P AddOperation eID, op t5jZ8&M5] Print "Set lens thickness = " & tlens 8K0@*0 e2$k
%c~ '************************************************************************* 8iwqy0< 'Lens index of refraction N?krlR '************************************************************************* sc
&S0K eID = FindMaterial( "Lens" ) ^K
n{L GetModelMaterial eID, mat %oqC5O6 w#\*{EN mat.Nd = nlens z\?cazQ SetModelMaterial eID, mat T_*R^Ukb5 Print "Set lens index of refraction = " & nlens \-~TW4dYe &Ew{ {t;" '************************************************************************* 7Q3a0`Iq 'Pupil diameter =dTsGNz '************************************************************************* e|jmOYWG eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 6l-V%3- CP!>V:w%9! 'Adjust pupil diameter (trimming volume inner hole) 0x]WW|se* !/Wp0E'A SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Y1Qg|U o 4` zfrT^ ' Adjust pupil location to just in front of the lens V8{5 y
<Y> parID = FindFullName( "Geometry.Arizona Eye" ) -<Zs7( eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 3G)Wmmh"a count = 0 \5s#9 While GetOperationCount(eID)>count fd}
Ul GetOperation eID, count, op WN%KATA If op.Type="ShiftZ" Then [exIK DeleteOperation eID,count _.y0QkwV count=count-1 WbW@V_rr End If Ot#O];3 count=count+1 =UW!
7OzC Wend T,eP&IN op.Type = "ShiftZ" ypK1
sw op.val1 = taq-0.01
B1!b@0^ op.parent = parID ow{Ss X AddOperation eID, op }+4^ZbX+: Q-g}{mFS Print "Set pupil diameter = " & pupilDiam W{!GL %t:pG}A>:C 'Update AZ Eye subassembly Description xVn"xk eID = FindFullName( "Geometry.Arizona Eye" ) ToWtltCD GetEntity eID, entity Eu^?e entity.Description = "Accommodation = " & A & "D" bijE]:<AE7 SetEntity eID, entity 8NRc+@f|m 39(]UO6^; Update /X_g[*]? Print "DONE!" bEJz>oyW" 05cyWg9a End Sub J<4egk4 sw'?&:<"Ow 如果屈光度是4,光瞳直径是4,则会输出如下数据: Pgg\(D#X` Y]SX2kk(2 Accommodation = 4 Diopters ]_ WB^ Pupil Diameter = 4 mm NlS/PWc6( Set aqueous humor thickness = 2.81 =E?!!EIq. Set anterior lens radius = 10.4 and conic constant = -2.375869 ;/Z9M"!u[ Set posterior lens radius = -4.424557 and conic constant = -3.081019 x!08FL) Set lens thickness = 3.927 VdZmrq;?/ Set lens index of refraction = 1.42672 v0yaFP#kG Set pupil diameter = 4 Ikn)XZU^ DONE! V{j>09u Gw5j6
e)WpqaI QQ:2987619807 1j7sJ" *
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