Arizona眼睛模型
简介 SSl8 ,-w-su=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。 :DS2zA [Q2S3szbt6 模型 <Tj"GVZAEO oO! 1 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。 S3%.-)ib pko!{,c
Table 1. AZ眼睛模型的定义 F{a0X0ru~ 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. jhjW*F<u =:t@;y 光源 gb!@OZ c l%-67( 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。 .FfwY 'V =)"NE> 0 .6X{kO
图1. 光源和提示信息使用 `dG.L 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。 6xDl=*&% sRo<4U0M;l 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。 ,d9%Ce.$2 a"v"n$
图2. 字母F光源的设定方法光 lOowMlf@2 ZNL;8sI?>
图3. 字母F在视网膜上位置点列图 >#"jfjDuR 视网膜的散射 %x cM_|AyR `Yo-5h 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。 U5@TaGbx ne!j%9Ar Knw'h;,[
图4. 视网膜朗伯散射设定 thlpj*| 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。 0`g}(}'L 7Ap~7)z[ hy!'Q>[`
图5. 视网膜重点采样规格设定 e"v[)b++Y 脚本 LX(iuf+l ~vjr;a(B 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: V,|Bzcz `a/PIc"
图6. 用户对话框的创建与编辑 kMJQeo79
图7. 用户对话框编辑器 !~w6"%2+7 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。 Xn
ZX *Y]" 余下的脚本计算与屈光度有关的所有参数。 }v'PY/d. Eezlx9b 分析 }LHT#{+x C>k;Mvq 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。 Je4.9?Ch (to/9OrG
图7. 字母F在视网膜上颜色分析 Z CQt1; 脚本代码 u75)>^:I <g/(wSl Option Explicit 'Remove this to enable non-dimensioned variables to be used. >zfZw"mEP Nak'g/uP> Dim entity As T_ENTITY 5u
u2 _B_L Dim op As T_OPERATION yG4LQE Dim mat As T_MODELMATERIAL &[W3e3Asra Dim A As Double P98X[0& Dim pupilDiam As Double D<D
k1 Dim eID As Long $@:>7Y" Dim parID As Long KHc/x8^9 Dim count As Integer #BT6bH08X Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double g.`t!6Hc Dim tlens As Double, nlens As Double :}3qZX Dim curv As Double, conic As Double !rsqr32] Dim ok As Long oZ*=7u xJF6l!` Sub Main v{rK_jq n[MIa]dK '用户输入对话框 u=v%7c2Mx} Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 zoJkDr=jn TextBox 220,21,40,21,.TextBox1 'default: 0 =Zb"T5E Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 13_+$DhU-L OKButton 40,91,90,21 >gOI]*!5 CancelButton 190,91,90,21 Edn$0D68u_ Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 4f*Ua`E_ TextBox 220,49,40,21,.TextBox2 'default: 4 Y9co?!J 5M End Dialog ]\9B?W(# Dim dlg As UserDialog 1R+ )T'in M;vlQ"Yl' ok = Dialog (dlg) \Zz= 4
j 2cX"#."5p If ok=0 Then 'cancel button was pressed M:1F@\< Print "Execution cancelled." sKG~<8M} End lJ>QTZH!wW End If l"pz
)$eE B,m$ur#$ 'Assign accommodation and pupil diameter & use defaults if field left empty @<w9fzi If dlg.TextBox1 = "" Then Mp=kZs/ A = 0 'Default accommodation TLL[F;uZ Else O"s`-OM;n A = CDbl(dlg.TextBox1) M@2Qn-I End If 5 dNf$a0E #u2&8-Gh If dlg.TextBox2 = "" Then '*LN)E>d pupilDiam = 4 'Default pupil diameter LG@c)H74 Else !wR{Y[Yu pupilDiam = CDbl(dlg.TextBox2) fF-\TW End If l^eNZ3:H 8|-mzb& Print " " D@b<}J>0' Print "Accommodation = " & A & " Diopters" t ]I(98pY Print "Pupil Diameter = " & pupilDiam & " mm" ':R3._tw\ ?o(X0 ' Calculate new parameters with accommodation /HJ(Wt
q taq = 0.55 + 2.97 - 0.04*A 'Aqueous thickness =*>4Gh
i u+tb83~[= Rant = 12.0 - 0.4*A 'Radius of anterior lens +D-+}&oW CCant = -7.518749 + 1.285720*A 'Conic constant of anterior lens \`%Y-!H+v =|JIY Rpost = -5.224557 + 0.2*A 'Radius of posterior lens wyA(}iSq CCpost = -1.353971 - 0.431762*A 'Conic constant of posterior lens (#l_YI
- 0qd;'r< tlens = 3.767 + 0.04*A 'Lens thickness =wR]X*Pan O\8|niW| nlens = 1.42 + 0.00256*A - 0.00022*A^2 'Lens index of refraction Lvj5<4h;
IOSoc 7+" 'Adjust parameters to account for accommodation \gzwsT2& _Il9s#NA% '************************************************************************* >8fz ?A 'Aqueous thickness (Position of Lens) v7OV;ea$ '************************************************************************* I7z]%Z eID = FindFullName( "Geometry.Arizona Eye.Lens" ) JO^
[@ GetCustomElement eID, entity >]Yha}6h #IrP"j^ parID = FindFullName( "Geometry.Arizona Eye" ) '%RK KA gsR9M%mv ' Delete any shift(s) in z aE cg_es count = 0 *_K-T# While GetOperationCount(eID)>count &@iF!D\u GetOperation eID, count, op pr,1Wp0l If op.Type="ShiftZ" Then -Tkd@ DeleteOperation eID,count &?Z)V-1H count=count-1 ?G>TaTiK# End If E!~2\qKT count=count+1 q.b4m 'J Wend dQ|Ht[s= C<@1H>S4_ 'Set new shift in l}-`E@w op.Type = "ShiftZ" =bg&CZVT op.val1 = taq ?_j6})2zY op.parent = parID z*~PYAt AddOperation eID, op 0#{]!>R Print "Set aqueous humor thickness = " & taq-0.55 Yg,lJ!q qe"6#@b *| '************************************************************************* jMWwu+w 'Radius and conic constant of anterior lens vMdhNOU '************************************************************************* & c9Fw:f; eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) FRQ("6( GetConic eID, entity, curv, conic k8wi-z[dV $,zM99 SetConic eID, entity, 1/Rant, CCant X6*y/KGN Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 14YV#o: kCjI`=7$[ '************************************************************************* >upUY(3& 'Radius and conic constant of posterior lens j~f 7WJ '************************************************************************* SWO!E eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) y*Q-4_%, GetConic eID, entity, curv, conic "v(]"L rZQHB[^3 SetConic eID, entity, 1/Rpost, CCpost 2pNJWYW" Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 5
^J8<s@_ +pViHOJu&V '************************************************************************* I"<.
h' 'Lens thickness (Position of posterior lens surface) K}3"K C '************************************************************************* [Q_|6Di EjE`S_i= parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5f@YrTO[@ d]~1.i ' Delete any z-shift(s) A?k,}~ count = 0 9,> Y While GetOperationCount(eID)>count )mVYqlU" GetOperation eID, count, op ^K8a#- If op.Type="ShiftZ" Then t\d;}@bl DeleteOperation eID,count 5nqdY* count=count-1 l"y9XO| End If pYUkd!K" count=count+1 }gRLW2&mR> Wend g}r5ohqC# ?ML<o>OKg 'Set new z-shift WR EGRy op.Type = "ShiftZ" Jd6Q 9~z# op.val1 = tlens 8&hn$~ate op.parent = parID 5MU@g*gj,C AddOperation eID, op >Nl~"J|]q Print "Set lens thickness = " & tlens \1D,Kx;Cb 2_v+q '************************************************************************* ,8?*U]} 'Lens index of refraction sn`?Foh '************************************************************************* HcS^3^Y eID = FindMaterial( "Lens" ) ([o:_5/8I GetModelMaterial eID, mat >(KUYX?p Yx c >+mx mat.Nd = nlens y+R$pzX SetModelMaterial eID, mat m?G+#k;K Print "Set lens index of refraction = " & nlens t1s@Ub5);I W?Abx '************************************************************************* 9gayu<J 'Pupil diameter tzJtd '************************************************************************* )X$n'E eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ` &7?+s Z i&X ,K~ 'Adjust pupil diameter (trimming volume inner hole) yE{UV>ry xl=|]8w SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" q`zR 6 iPNsEQ0We ' Adjust pupil location to just in front of the lens }gaKO 5 parID = FindFullName( "Geometry.Arizona Eye" ) ~36XJ eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Z9bPj8d count = 0 vG:,oB} While GetOperationCount(eID)>count u)>*U'bM GetOperation eID, count, op B%;+8] If op.Type="ShiftZ" Then 0k]N%!U DeleteOperation eID,count |<icx8hbr count=count-1 -bQvJ`iF End If 0_izTke count=count+1 (I
g
*iJ%2 Wend nwH|Hs riU op.Type = "ShiftZ" Ia"
Mi+{ op.val1 = taq-0.01 hV>Ey^Ty op.parent = parID J3^Ir [ AddOperation eID, op NPab M(<` 36UWoo Print "Set pupil diameter = " & pupilDiam v>l?d27R ,aL"Wy( 'Update AZ Eye subassembly Description w=2X[V} eID = FindFullName( "Geometry.Arizona Eye" ) r${a
S@F GetEntity eID, entity >.>5% entity.Description = "Accommodation = " & A & "D" 'iK*#b8l SetEntity eID, entity Q"uu&JC B`Pi\1H6% Update 0C_Qp% Z Print "DONE!" I!~Omr@P 1N*~\rV*? End Sub <{j9|mt f}3bYF 如果屈光度是4,光瞳直径是4,则会输出如下数据: !{\c`Z<# "5bk82." Accommodation = 4 Diopters Hq8.O/Y"= Pupil Diameter = 4 mm ZrBxEf$f Set aqueous humor thickness = 2.81 ${3OQG Set anterior lens radius = 10.4 and conic constant = -2.375869 b2H6}s"=w Set posterior lens radius = -4.424557 and conic constant = -3.081019 4 -W?u51" Set lens thickness = 3.927 &2^V<(19 Set lens index of refraction = 1.42672 ['j,S<Bu~ Set pupil diameter = 4 $!lxVZ> DONE! ) 'KHUa9 nK$m:= ]T`qPIf;yJ QQ:2987619807 hG]20n2
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