Arizona眼睛模型

'<-F 3   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。 >&`;@ZOH   @aY>pr5!   模型 tLSM]Q   AXT(D@sI=   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。 ZZ2vdy38   Table 1. AZ眼睛模型的定义 2qpUUo f   )PCh;P0C   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. iOXsj   /ht-]Js$G   光源 '1vm]+oM   1)v]<Ga~%1   多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 Scd_tw.]|   }!*CyO*   图1. 光源和提示信息使用 : sA$LNj}   PQvpJFpb~h   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。 v\3$$T)   x=YV*   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。 \#7@"~<   图2. 字母F光源的设定方法光 @ebSM#F?   lOEB ,/P   图3. 字母F在视网膜上位置点列图 Q/]t$   ~ya@ YP]';   视网膜的散射 ^t}8E2mq   O/Mx$Q3re   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 R q9(<'F   Ng|c13A=   图4. 视网膜朗伯散射设定 I4(z'C   @XQItc<   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 ,~*pPhQ8m   X[J?   图5. 视网膜重点采样规格设定 0HPqoen$   D]'/5]~z<   脚本 U# g,XJ   Jk}Dj0o   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： GZzBATx   图6. 用户对话框的创建与编辑 QE4TvnhK   图7. 用户对话框编辑器 P-?R\(QYtR   <~}NxY\5   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。 (-%1z_@Y   余下的脚本计算与屈光度有关的所有参数。 Dks"(0g   }e]tn)   分析 t{Wu5<F:    |Sr   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 :CGh$d] +   图7. 字母F在视网膜上颜色分析 =-E%vnU   m8<.TCIQ   脚本代码 iyTKy+3A   9o+e3TXp#   Option Explicit     'Remove this to enable non-dimensioned variables to be used. "U|u-ka8B   E-v^eMWX   Dim entity As T_ENTITY c" oJcp   Dim op As T_OPERATION -9;XNp   Dim mat As T_MODELMATERIAL nO `R++   Dim A As Double ]o($No   Dim pupilDiam As Double X}ft7;Jpy   Dim eID As Long aSt:G*a"   Dim parID As Long o}e]W,   Dim count As Integer @n^2UJ   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double :vJ1Fo!   Dim tlens As Double, nlens As Double dhV6r   Dim curv As Double, conic As Double /|p6NK;8L   Dim ok As Long *?YMoN   _<u>? Qt   Sub Main #k|f%!-Vo   -+fW/Uo       '用户输入对话框 4uE|$       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 j7yUya&           TextBox 220,21,40,21,.TextBox1 'default: 0 z-JYzxL9           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ;4k/h/o1#           OKButton 40,91,90,21 8fA8@O}           CancelButton 190,91,90,21 ?/}-&A"           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 A7R [~           TextBox 220,49,40,21,.TextBox2 'default: 4 Bk@&k}0       End Dialog 46D_K       Dim dlg As UserDialog @umn#*   WZN0`Od       ok = Dialog (dlg) Oid;s!-S6   ~F[JupU       If ok=0 Then    'cancel button was pressed wUKt$_]``           Print "Execution cancelled." G]T&{3g-.           End G;AJBs>Y}       End If G2w0r,[   bKQ_{cR       'Assign accommodation and pupil diameter & use defaults if field left empty B4{F)Zb       If dlg.TextBox1 = "" Then `<(o;*&Gd           A = 0           'Default accommodation lyw)4;wt\       Else ~\u~>mtchu           A = CDbl(dlg.TextBox1) [/U5M>#n       End If 4[rX\?^e   <])kO` +G       If dlg.TextBox2 = "" Then wit           pupilDiam = 4   'Default pupil diameter J<MuWgx&       Else nU/x,W[}           pupilDiam = CDbl(dlg.TextBox2) 7T?T0x3>       End If /X;! F>   \L"0Pmt[       Print " " a0PClbf2.       Print "Accommodation = " & A & " Diopters" GpXU&A'r       Print "Pupil Diameter = " & pupilDiam & " mm" ZJV;&[$[   q OV$4[r       ' Calculate new parameters with accommodation ~|&To>       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 3bagL)'iz   Rts.jm>[       Rant = 12.0 - 0.4*A                     'Radius of anterior lens >S@><[C       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens )<`/Aaie   : 2A\X' @       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens O +Xu?W]       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens +kx#"L:   H(DI /"N       tlens = 3.767 + 0.04*A                  'Lens thickness H={5>;8G   N3ccn       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction &XB1=b5   B6U4>ZN       'Adjust parameters to account for accommodation s[%@3bY!7   ZmS ]4WM<       '************************************************************************* scyv]5Hm!       'Aqueous thickness (Position of Lens) yH(%*-S       '************************************************************************* ]Uul~T       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) &"=<w       GetCustomElement eID, entity +@MG$*}Oz   /U=?D(>x       parID = FindFullName( "Geometry.Arizona Eye" ) 86W.z6   |z`AIScT       ' Delete any shift(s) in z %D>cY!       count = 0 h%] D[g       While GetOperationCount(eID)>count UxvT|~"           GetOperation eID, count, op `t2Y IwOK           If op.Type="ShiftZ" Then )| F O>               DeleteOperation eID,count HJ!P]X_J1               count=count-1 D:XjJMW3r           End If z`!f'I--!           count=count+1 > (Fy6m       Wend +m1*ou'K   jR"ACup(       'Set new shift in \1oN't.       op.Type = "ShiftZ" { P@mAw       op.val1 = taq .s>.O6(^%       op.parent = parID Ex5LhRe>=       AddOperation eID, op 5$c*r$t_RK       Print "Set aqueous humor thickness = " & taq-0.55 43 Ua@KNi   >Dq&[9,8       '************************************************************************* IhXP~C6       'Radius and conic constant of anterior lens ^@;P-0Sy       '************************************************************************* Z(BZGO<       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 6,(S}x YDZ       GetConic eID, entity, curv, conic ZQ[s/   -fDW>]_       SetConic eID, entity, 1/Rant, CCant _aw49ag;       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant % {A%SDh   d>Ky(wS       '************************************************************************* !$#8Z".{v{       'Radius and conic constant of posterior lens 34t[]v|LD       '************************************************************************* Z+ )<FX       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) iM~qSRb#mJ       GetConic eID, entity, curv, conic O[R    Q;=3vUN       SetConic eID, entity, 1/Rpost, CCpost h/7_IuD       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost z*`nfTw l   2 P9{?Y       '************************************************************************* A3Y}|7QA       'Lens thickness (Position of posterior lens surface) ] jycg@=B       '************************************************************************* TJs~}&L   **F-#",       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ._(5; PB"   :CG;:( |       ' Delete any z-shift(s) V(OD^GU       count = 0 _q`f5*Z[       While GetOperationCount(eID)>count -{Fy@$!           GetOperation eID, count, op Yw,LEXLY           If op.Type="ShiftZ" Then *zWf8X               DeleteOperation eID,count ^2uT!<2               count=count-1 |L~RC           End If eI+p           count=count+1 v.Xmrry       Wend >/y+;<MZ   K<fB]44Y       'Set new z-shift iH)-8Q       op.Type = "ShiftZ" Zmy:Etqi       op.val1 = tlens ,pa=OF       op.parent = parID _OJ19Ry       AddOperation eID, op .%_=(C<E       Print "Set lens thickness = " & tlens Yn8aTg[J   s^GE>rf       '************************************************************************* c)zwyBz       'Lens index of refraction m=%yZ2F;       '************************************************************************* 8C<%Y7)/       eID = FindMaterial( "Lens" ) M$2lK^2L       GetModelMaterial eID, mat ! }L cJ   Fy^MI*}BZ       mat.Nd = nlens t#=FFQOt       SetModelMaterial eID, mat gU@BEn}       Print "Set lens index of refraction = " & nlens Ia-nA|LBxI   J;Veza       '************************************************************************* `yrJ}f       'Pupil diameter k4YW;6<C+       '************************************************************************* n4/Jx*       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) I=&Kn @^   ^q/_D%]C       'Adjust pupil diameter (trimming volume inner hole) A(wuRXnVWK   M[?0 ^ FBx       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" myDcr|j-a   Cm#[$T@C       ' Adjust pupil location to just in front of the lens >:f&@vwm       parID = FindFullName( "Geometry.Arizona Eye" ) Dh .<&ri       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) P#qQde/y       count = 0 YFs!,fw'       While GetOperationCount(eID)>count B-[qS;PY%           GetOperation eID, count, op cGS7s 8U           If op.Type="ShiftZ" Then 2g%p9-MO]I               DeleteOperation eID,count `h$^=84               count=count-1 kTm>`.kKJ=           End If ![{0Yw D           count=count+1 "[\),7&03       Wend OLyl.#J       op.Type = "ShiftZ" #~6au6LMC       op.val1 = taq-0.01 | gP%8nh'C       op.parent = parID X&cm)o%5Fe       AddOperation eID, op ' "J``=   ~3qt<"       Print "Set pupil diameter = " & pupilDiam }Z8DVTpX}   i3o;G"IcD       'Update AZ Eye subassembly Description vXeI)vFK       eID = FindFullName( "Geometry.Arizona Eye" ) %lSjC%Z'd       GetEntity eID, entity qruv^#_l       entity.Description = "Accommodation = " & A & "D" I.u[9CI7HU       SetEntity eID, entity )H-y   Oq*=oz^~1       Update aui3Mq#f       Print "DONE!" '*n2<y        #]lK!:   End Sub XJZS}Z7h   n@y*~sG]   如果屈光度是4，光瞳直径是4，则会输出如下数据： eX <@qa4<   ?7R&=B1g   Accommodation = 4 Diopters 4'`y5E   Pupil Diameter = 4 mm 4pZ=CB+j   Set aqueous humor thickness = 2.81 i|QL6e*0   Set anterior lens radius = 10.4 and conic constant = -2.375869 )(l=_[1Z5   Set posterior lens radius = -4.424557 and conic constant = -3.081019 _?a.S8LxJZ   Set lens thickness = 3.927 U$ 22r b   Set lens index of refraction = 1.42672 )P # MUC   Set pupil diameter = 4 Z'o'd_g>I+   DONE!

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