Arizona眼睛模型

4H\O&pSS   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。 }Pw5*du q   >n` OLHg;   模型 NWoZDsu   B /Dj2   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。 av`b8cGg   Table 1. AZ眼睛模型的定义 {P = {)   Y-9]J(   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. <`MHra8   2<B+ID3qv   光源 <GoE2a4Va   c/g(=F__[   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。 -$T5@   gHox{*hb[   图1. 光源和提示信息使用 4@8i,q>   TOBAh.1   除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 qqkZbsN   TFM} P   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 2etlR   图2. 字母F光源的设定方法光 FWD9!M K   9V"^F.>   图3. 字母F在视网膜上位置点列图 SM^6+L"BE   4Y-9W2s   视网膜的散射 9k83wACry   A:p0p^*   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 5[Q44$a{   8PQ$X2)   图4. 视网膜朗伯散射设定 q<;9!2py   Mq*Sp UR   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 FE_n+^|k<   `qfVgT=2   图5. 视网膜重点采样规格设定 VvoJ85   6\E |`   脚本 G`)I _uO   Zj}DlNkVu   内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： !XtbZ-   图6. 用户对话框的创建与编辑 Dnd   图7. 用户对话框编辑器 ~&KfJ   4!monaB"e   如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 3mBrnq]j>   余下的脚本计算与屈光度有关的所有参数。 *, {b]6v   {8UBxFIM(   分析 SSH/q/   !(o)*S   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 Ay2|@1e   图7. 字母F在视网膜上颜色分析 H5qa7JMZ   f|b|\/.=   脚本代码 Ke\?;1+   @<w$QD   Option Explicit     'Remove this to enable non-dimensioned variables to be used. b[u_r,b   5E.cJ{   Dim entity As T_ENTITY ^pg5o)M   Dim op As T_OPERATION #s]]\   Dim mat As T_MODELMATERIAL KIuYWr7&   Dim A As Double ETtK%%F0   Dim pupilDiam As Double S&R~*   Dim eID As Long qed; UyN   Dim parID As Long )Wc#?K   Dim count As Integer ~xXB !K~C   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double t[^}/ S   Dim tlens As Double, nlens As Double l+T\DZ   Dim curv As Double, conic As Double uQ&xoDCB   Dim ok As Long !E$S&zVMQ   ['sIR+c%'O   Sub Main -R:1-0I$   D6v0n6w       '用户输入对话框 .oSKSld       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 3[8'pQ!&           TextBox 220,21,40,21,.TextBox1 'default: 0 !'PPj_Hp]           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 |1t30_ /gS           OKButton 40,91,90,21 s+0$_&xR           CancelButton 190,91,90,21 N"2@yaN           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 w0 "h,{           TextBox 220,49,40,21,.TextBox2 'default: 4 `;i| %$TU       End Dialog mX"z$       Dim dlg As UserDialog "e(OO/EZS   wN*e6dOF       ok = Dialog (dlg) BD9` + 9   ,Q}/#/       If ok=0 Then    'cancel button was pressed ~){*XJw6           Print "Execution cancelled." [#14 atv           End e[{LNM{/#       End If Z\@vN[[   &5zUk++       'Assign accommodation and pupil diameter & use defaults if field left empty ;E# #bdSCA       If dlg.TextBox1 = "" Then w8@Ok_fj           A = 0           'Default accommodation KiCZEA       Else eo,m ^&           A = CDbl(dlg.TextBox1) N|Rlb5\       End If LkNfcBa_   ImvkB~8N       If dlg.TextBox2 = "" Then "qwRcuHY           pupilDiam = 4   'Default pupil diameter C~6aX/:       Else hbN*_[           pupilDiam = CDbl(dlg.TextBox2) ~A"ODLgU9       End If N*@bJ*0   $`]<4I9d       Print " " TmO\!`       Print "Accommodation = " & A & " Diopters" Iye       Print "Pupil Diameter = " & pupilDiam & " mm" ?(ks=rRK   lW7kBCsz#       ' Calculate new parameters with accommodation 2 Ie50U       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Hm4lR{A   q9!5J2P       Rant = 12.0 - 0.4*A                     'Radius of anterior lens &_!BMzp4       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ,`H= %#   )zr/9aV       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens #7'ww*+       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens @ZT25CD   J }JT%SW       tlens = 3.767 + 0.04*A                  'Lens thickness :X@;XEol~   >5]Xl*{H)       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction x}F.<`   7E|0'PPR       'Adjust parameters to account for accommodation x)V.^-   @tp/0E?       '************************************************************************* pY-izML       'Aqueous thickness (Position of Lens) Ry/NfF=       '************************************************************************* #<se0CJB       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0MPsF{Xw[       GetCustomElement eID, entity r+ v tKb   in B}ydk       parID = FindFullName( "Geometry.Arizona Eye" ) kv)LH{   WhK?>u       ' Delete any shift(s) in z 93YD\R+q       count = 0 =Jem.Ph       While GetOperationCount(eID)>count ZZlR:D           GetOperation eID, count, op xcoYo           If op.Type="ShiftZ" Then .W?POJT               DeleteOperation eID,count RV&2y=eb               count=count-1 vy-{BH           End If W*8D@a0 _           count=count+1 }H^#}       Wend &I d^n   6x -PGq       'Set new shift in #= $4U!yL       op.Type = "ShiftZ" V <k_Q@K       op.val1 = taq ]kc_wFT<       op.parent = parID 3ON]c13       AddOperation eID, op $H5PB' b       Print "Set aqueous humor thickness = " & taq-0.55 `cZG&R   SxQ|1:i%       '************************************************************************* +ES.O]?>       'Radius and conic constant of anterior lens >A1Yn]k       '************************************************************************* s"a*S\a;b       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) KAUYE^       GetConic eID, entity, curv, conic 6W#+U<   vtvr{Uqo@       SetConic eID, entity, 1/Rant, CCant JgK?j&!hs:       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant !!` zz   fM2[wh@       '************************************************************************* Z{ p;J^:       'Radius and conic constant of posterior lens gR?3)m       '************************************************************************* R>Zn$%j\       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) $_)f|\s       GetConic eID, entity, curv, conic A+[wH(   FtF!D tv       SetConic eID, entity, 1/Rpost, CCpost m"v` E7G       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost g%\e80~1(   ;$0za]x       '************************************************************************* j^64:3       'Lens thickness (Position of posterior lens surface) MvRuW:       '************************************************************************* k$+&   <F!:dyl       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Ex*g>~e   ,e>ugI_;*       ' Delete any z-shift(s) $G=\i>R.       count = 0 "4r 5n8       While GetOperationCount(eID)>count zu;Yw=cM)           GetOperation eID, count, op `zep`j&8^           If op.Type="ShiftZ" Then M)b`~|Wt               DeleteOperation eID,count 6 a$%               count=count-1 +_`F@^R_           End If C-2n2OM.           count=count+1 Gn_v}31d%       Wend neZ_TT/ 3K   m7!l3W2       'Set new z-shift s"Kp+tTWj       op.Type = "ShiftZ" xK_$^c.       op.val1 = tlens j5ui       op.parent = parID )}6:Ke)       AddOperation eID, op %/>_o{"hw       Print "Set lens thickness = " & tlens m+vwp\0   TZHqn6       '************************************************************************* 0,/[r/=jT       'Lens index of refraction b,K1EEJ       '************************************************************************* 7,O^c+       eID = FindMaterial( "Lens" ) !BQ!]u       GetModelMaterial eID, mat T]i~GkD\   cu""vtK        mat.Nd = nlens S[ 2`7'XV       SetModelMaterial eID, mat j#~4JGZt       Print "Set lens index of refraction = " & nlens &V2G<gm0   *&AK.n_       '************************************************************************* 1yE~#KpH       'Pupil diameter $~9U-B\       '************************************************************************* q$HBPR4h       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) kW(8i}bg   `[ne<F?e       'Adjust pupil diameter (trimming volume inner hole) v=W%|iZ   ~MQN&       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" }M9'N%PU   c76^x        ' Adjust pupil location to just in front of the lens 82w<q(       parID = FindFullName( "Geometry.Arizona Eye" ) ll5Kd=3       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) \zoJr)       count = 0 |0Zj/1<$       While GetOperationCount(eID)>count 8)H"w $jq           GetOperation eID, count, op <LLSUk/           If op.Type="ShiftZ" Then M.l;!U!}               DeleteOperation eID,count I]$kVa1iN               count=count-1 ^7_<rs           End If m.4y=69 &           count=count+1 q|6lw 74`       Wend 7"S|GEs:       op.Type = "ShiftZ" oF3#]6`;/       op.val1 = taq-0.01 %8$wod6       op.parent = parID I4");T3       AddOperation eID, op {uhw ^)v   ksK lw_%o       Print "Set pupil diameter = " & pupilDiam '<@PgO~   MZ+"Arzb       'Update AZ Eye subassembly Description nH_A`m3%/       eID = FindFullName( "Geometry.Arizona Eye" ) 66BsUA.h       GetEntity eID, entity oZzE.Q1T       entity.Description = "Accommodation = " & A & "D" nGu F,0j       SetEntity eID, entity `bxgg'V   =F:d#j>F       Update B)c.`cfr*\       Print "DONE!" Nd( $s[        %b_zUFHPp   End Sub lvFHr}W   z3$PrK%   如果屈光度是4，光瞳直径是4，则会输出如下数据： ciXAyT cG   \^YJs?   Accommodation = 4 Diopters $AX!L+<!   Pupil Diameter = 4 mm 00$W>G r   Set aqueous humor thickness = 2.81 eH6#'M4+\   Set anterior lens radius = 10.4 and conic constant = -2.375869 \@80Z5?n   Set posterior lens radius = -4.424557 and conic constant = -3.081019 SWmdU]   Set lens thickness = 3.927 b.t]p   Set lens index of refraction = 1.42672 uS&bfx2   Set pupil diameter = 4 5ax/jd~}   DONE!

a1j6-p

3|~(9b{+