Arizona眼睛模型

5}f$O   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。 Z|u_DaSrr|   X@B+{IFC   模型 *<KY^;   Q"KH!Bu%P   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。 l ^{]pD   Table 1. AZ眼睛模型的定义 &"=inkh   +IMP<   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. eb7`R81G   =^6]N~*,D   光源 :E.mU{   L_/.b%0)   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。 fV3J:^)F   +K&ze:-Z   图1. 光源和提示信息使用 xi^_C!*J   2e+DUZBoC   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。 0&<{o!>k   p!=/a)4X   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。 wEk9(|   图2. 字母F光源的设定方法光 h)sc-e   % 30&6"   图3. 字母F在视网膜上位置点列图 zg]9~i8   y2)~ljR   视网膜的散射 ).LJY<A   RP6QS)|   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。 }V09tK/M   h|wyvYKZ   图4. 视网膜朗伯散射设定 =*t)@bn   Dp>/lkk.   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。 VF;%Z   ee6Zm+.B   图5. 视网膜重点采样规格设定 S-My6'ar   ! @|"84   脚本 PM,I?lJ,   l]GLkE   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： ktnsq&qNL   图6. 用户对话框的创建与编辑 /1Ndir^c   图7. 用户对话框编辑器 IpHGit28   ZjbMk3Y   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。 TEv3;Z*N   余下的脚本计算与屈光度有关的所有参数。 fi`*r\   p9fx~[_5/   分析 kz]qk15w   ge*f<#|0U-   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 !Vy/-N   图7. 字母F在视网膜上颜色分析 Iq(B H^K   XNsMXeO]&   脚本代码 Ee^2stc-   PU[] Nw   Option Explicit     'Remove this to enable non-dimensioned variables to be used. [/\}:#MLe   A(ql}cr   Dim entity As T_ENTITY "p0e6Z=   Dim op As T_OPERATION .*i.Z    Dim mat As T_MODELMATERIAL w_PnEJa9   Dim A As Double 0;KjP?5   Dim pupilDiam As Double +uLl3(ml   Dim eID As Long }mz@oEB#vF   Dim parID As Long m>DBO |`   Dim count As Integer \'x.DVp   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double $zKf>[K   Dim tlens As Double, nlens As Double PS**d$ S   Dim curv As Double, conic As Double CN+[|Mz*p   Dim ok As Long M:rE^El   %xPJJ$P   Sub Main M*$#j|   V\vt!wBcB       '用户输入对话框 7M7sq-n5z       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 yp9vgUs           TextBox 220,21,40,21,.TextBox1 'default: 0 c<fl6o)           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 }Ox5,S}ra           OKButton 40,91,90,21 M8(N9)N           CancelButton 190,91,90,21 }fU"s"           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 8`Ih> Dc           TextBox 220,49,40,21,.TextBox2 'default: 4 #?u#=]       End Dialog K!g!tA$       Dim dlg As UserDialog v)1@Ew=Y%   h&}z@       ok = Dialog (dlg) _X;xW#go   }xJ ).D       If ok=0 Then    'cancel button was pressed (.^KuXd           Print "Execution cancelled." #\1)Tu%-           End N.(wR       End If 'A2^K5`3   kT^|%bB[i       'Assign accommodation and pupil diameter & use defaults if field left empty QN)EPS:y       If dlg.TextBox1 = "" Then ecvQEK2L           A = 0           'Default accommodation m9Xauk$ (       Else a!guZUg6           A = CDbl(dlg.TextBox1) \ ]v>#VXr_       End If JP{Y Q:NF   S3Dmc\f       If dlg.TextBox2 = "" Then ZB+~0[C           pupilDiam = 4   'Default pupil diameter efN5(9*9R       Else a1#",%{I           pupilDiam = CDbl(dlg.TextBox2) CT{mzC8       End If c'md)nD2M   L+K,Y:D!W       Print " " OJ?U."Lxm$       Print "Accommodation = " & A & " Diopters" ++\s0A(e       Print "Pupil Diameter = " & pupilDiam & " mm" ze"`5z26|   ({$>o]<h       ' Calculate new parameters with accommodation MMU>55+-       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness W>y>   :6TLT-B       Rant = 12.0 - 0.4*A                     'Radius of anterior lens !:2_y'hA       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens `}.jH1Fx/m   #kQ1,P6,(       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens U2G[uDa;       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 9s4>hw@u   xcE2hK/+       tlens = 3.767 + 0.04*A                  'Lens thickness <I 0EjV   6qR5A+|;       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 'IQ;;[Q   a! gj_       'Adjust parameters to account for accommodation yRy^'E~   W %<,GV       '************************************************************************* y/Ui6 D       'Aqueous thickness (Position of Lens) `|p8zV       '************************************************************************* *E|#g       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) b?,''t       GetCustomElement eID, entity sq _ yu(   ^]k=*>{ R       parID = FindFullName( "Geometry.Arizona Eye" ) Ex<@:   w!r.MWE       ' Delete any shift(s) in z eWOZC(I*z       count = 0 Ug#EAV<m       While GetOperationCount(eID)>count )0o|u>           GetOperation eID, count, op NqC}}N\ ,           If op.Type="ShiftZ" Then @rE+H 5               DeleteOperation eID,count O:j=L{,d^               count=count-1 7*eIs2aY           End If ("s!t?!&YS           count=count+1 &ox5eX(       Wend AzMX~cd   ^tL]QE?|       'Set new shift in ^!6T,7B B       op.Type = "ShiftZ" )1/J5DI @8       op.val1 = taq wvI}|c       op.parent = parID )uO 3v       AddOperation eID, op CqLAtS X7       Print "Set aqueous humor thickness = " & taq-0.55 1`2lq~=GV   2m,t<Y;       '************************************************************************* ({<qs}H"       'Radius and conic constant of anterior lens 9w<k1j       '************************************************************************* GLA4O)       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ._p^0UxT       GetConic eID, entity, curv, conic N&G;`   Va$JfWef       SetConic eID, entity, 1/Rant, CCant Q"k #eEA       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant w|U7pUz   yK>s]65&       '************************************************************************* a?X#G/)       'Radius and conic constant of posterior lens QV8;c^EZ       '************************************************************************* ejpSbVJ       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) $aY:Z_s       GetConic eID, entity, curv, conic _]M:   2{01i)2y       SetConic eID, entity, 1/Rpost, CCpost Y'?{yx{       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost b?:SCUI   eY\!}) 5       '************************************************************************* =c#;c+a       'Lens thickness (Position of posterior lens surface) l8 XY       '************************************************************************* 9u1Fk'cxG,   2 W Wr./q       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) {^@qfkZ z^    WYW@%t       ' Delete any z-shift(s) X?SLYm@v       count = 0 +ooQ-Gh       While GetOperationCount(eID)>count kOV6O?h           GetOperation eID, count, op `l-R?C?*!           If op.Type="ShiftZ" Then 71G00@&w9D               DeleteOperation eID,count :Oc&{z?q               count=count-1 5wI j:s           End If \l?.VE D           count=count+1 S%7%@Qs"%       Wend 3& Fqd   M7gM#bv>L       'Set new z-shift An=Q`Uxt/       op.Type = "ShiftZ" u\@L|rh       op.val1 = tlens A[N>T\       op.parent = parID z1LY|8$G       AddOperation eID, op ]*\<k       Print "Set lens thickness = " & tlens :s nn-e0l   g&L $5       '************************************************************************* y0 qq7Dmu       'Lens index of refraction lPn&,\9@~       '************************************************************************* (=w ff5U       eID = FindMaterial( "Lens" ) )}SiM{g       GetModelMaterial eID, mat *Bx'g| u   ]|4mD3O       mat.Nd = nlens ?`Som_vKO       SetModelMaterial eID, mat q^+Z>        Print "Set lens index of refraction = " & nlens 3bMUsyJ2   kA(q-Re$B*       '************************************************************************* -1 _7z{.       'Pupil diameter bn8?-       '************************************************************************* J9`[Qy\       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) g<PdiVp+   2O)2#N       'Adjust pupil diameter (trimming volume inner hole) Vr<ypyC   2s8(r8AI       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Y\ G^W8   *!x/ia9       ' Adjust pupil location to just in front of the lens b}jLI_R{       parID = FindFullName( "Geometry.Arizona Eye" ) f>C|qDmT       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) be5NasC       count = 0 0Z>oiBr4       While GetOperationCount(eID)>count ~*uxKEH           GetOperation eID, count, op w\3'wD!           If op.Type="ShiftZ" Then {>=#7e-]               DeleteOperation eID,count 0B[eG49               count=count-1 kEs=N(           End If N3g?gb"Ex)           count=count+1 O"x/O#66       Wend R7!^ M       op.Type = "ShiftZ" T+|V;nP.       op.val1 = taq-0.01 4C_-MJI       op.parent = parID 5s2334G       AddOperation eID, op ?4}EhXR(   r&-Ir3[       Print "Set pupil diameter = " & pupilDiam ?#X`Eu   aXefi'!6       'Update AZ Eye subassembly Description g_w4}!|       eID = FindFullName( "Geometry.Arizona Eye" ) jZ>'q/       GetEntity eID, entity ICgyCsZ,       entity.Description = "Accommodation = " & A & "D" ^NTOZ0x~#       SetEntity eID, entity |d1%N'Ll   v]HiG_C       Update 0yxMIX       Print "DONE!" _[W`!#"        '((Ll   End Sub <U$A_]*w   X*'-^WM6   如果屈光度是4，光瞳直径是4，则会输出如下数据： s(I7}oRWsL   (FAd'$lhX}   Accommodation = 4 Diopters  <XxFR   Pupil Diameter = 4 mm /Iu._2   Set aqueous humor thickness = 2.81 fE/8;v! =   Set anterior lens radius = 10.4 and conic constant = -2.375869 jsvD[\P   Set posterior lens radius = -4.424557 and conic constant = -3.081019 &p$SFH?s   Set lens thickness = 3.927 ?y{C"w!    Set lens index of refraction = 1.42672 +xlxhF   Set pupil diameter = 4 :=tPC A=   DONE!

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