Arizona眼睛模型

Lb*KEF%s   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。 7T~M`$h   j8Z,:op   模型 =L6#=7hcl   5!-TLwl`j\   模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 bJ^JK   Table 1. AZ眼睛模型的定义 v^|U?   i\R0+O{   在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 5 ]xuU.w'   7|rH9Bc{U   光源 BZR{}Aj4pa   .~z'm$s1o   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。 @^{Hq6_`   rfXxg^   图1. 光源和提示信息使用 36d nS>4   ]9@:7d6   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。 &|yLTx   _|k$[^ln^   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 ] V D   图2. 字母F光源的设定方法光 .@1+}0   O-iE0t   图3. 字母F在视网膜上位置点列图 d2\!tJm   *~rj!N?;   视网膜的散射 }Zhe%M=}G   TlG>)Z@/   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 J<)qw   _Q V=3UWP   图4. 视网膜朗伯散射设定 B2`S0 H   ((y|?Z$   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。 1? >P3C   , X5.|9   图5. 视网膜重点采样规格设定 2q f|+[X   }nmlN   脚本 yR}.Xq/   `Sod]bO +U   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： t],a1I.gk   图6. 用户对话框的创建与编辑 2u{~35   图7. 用户对话框编辑器 kY0HP a   m/HT3<F   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。 Q|y}mC/   余下的脚本计算与屈光度有关的所有参数。 ~.a"jYb7A}   2TK \pfD   分析 ffKgVQux   lExQp2E   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 QM$UxWo-   图7. 字母F在视网膜上颜色分析 2"/MM2s   1gI7$y+?   脚本代码 GgO5 =|   HC`0Ni1   Option Explicit     'Remove this to enable non-dimensioned variables to be used. X>(1fra4   _]:b@gXUw   Dim entity As T_ENTITY =SDex.ZK]   Dim op As T_OPERATION o3WOp80hz   Dim mat As T_MODELMATERIAL `/| *u   Dim A As Double >XN[KPTa   Dim pupilDiam As Double dQ:,pe7A   Dim eID As Long dSI"yz   Dim parID As Long YAi-eL67l   Dim count As Integer Dy08.Sss   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Vaxg   Dim tlens As Double, nlens As Double "Ih3   Dim curv As Double, conic As Double \!KE_7HRu   Dim ok As Long 4jT6 h9%   B-I4(w($   Sub Main n Ja!&G&   7?lz$.*Avp       '用户输入对话框 "8za'@D"f       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 R'c*CLaiE           TextBox 220,21,40,21,.TextBox1 'default: 0 `kKssU<           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 )\wkVAm           OKButton 40,91,90,21 RB>=#03           CancelButton 190,91,90,21 )W\)37=.           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ]4~Yi1]           TextBox 220,49,40,21,.TextBox2 'default: 4 >a3m!`lq       End Dialog n,T &n       Dim dlg As UserDialog H4M=&"ll}   s.1F=u9a       ok = Dialog (dlg) Y;w|Fvjj+   kUBE+a6#       If ok=0 Then    'cancel button was pressed |mT%IR           Print "Execution cancelled." oXo >pl           End ~!uX"F8Xl       End If _|~Dj)z   "&L8d(ZuA       'Assign accommodation and pupil diameter & use defaults if field left empty =%_=!%       If dlg.TextBox1 = "" Then HwU9y           A = 0           'Default accommodation C T~6T&'       Else ^}  {r@F           A = CDbl(dlg.TextBox1) IIk_!VzT       End If ?XKX&ws   T CT8OU|       If dlg.TextBox2 = "" Then ^^q&VL           pupilDiam = 4   'Default pupil diameter @ZEBtM%.O       Else txEN7!           pupilDiam = CDbl(dlg.TextBox2) <ZT C^=3       End If ?mMM{{%(.   PRfq_:xy       Print " " !ooi.Oz*Tu       Print "Accommodation = " & A & " Diopters" 5(~Lr3v0       Print "Pupil Diameter = " & pupilDiam & " mm" XtCIUC{r,   k?=1q[RQH       ' Calculate new parameters with accommodation UfW=/T       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 5OM#_.p   TX)W.2u=       Rant = 12.0 - 0.4*A                     'Radius of anterior lens 7_~sa{1R.       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens %/dOV[/   3ynkf77cn       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens w_"d&eYdg0       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens j"Jf|Hq $   $f@YQN=       tlens = 3.767 + 0.04*A                  'Lens thickness Ry95a%&/s   wx-\@{E       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Kp7DI0~   'Agw~ &$       'Adjust parameters to account for accommodation cb-IRGF   <NZPLo F       '************************************************************************* j$T12       'Aqueous thickness (Position of Lens) ^%!{qAp}Z       '************************************************************************* $yU 5WEX       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 7U7!'xU       GetCustomElement eID, entity $:I{   9L$OSy|       parID = FindFullName( "Geometry.Arizona Eye" ) ^i@anbH   _l{~O       ' Delete any shift(s) in z ^cZ< .d2       count = 0 *VsGa<V       While GetOperationCount(eID)>count KHx2$*E_           GetOperation eID, count, op AL":j6!OQ           If op.Type="ShiftZ" Then =!-}q               DeleteOperation eID,count #ss/mvc3               count=count-1 n1%2sV)>           End If NL]_;\ h           count=count+1 4dixHpq'       Wend "{8j!+]4i   h: yJ       'Set new shift in D%+yp       op.Type = "ShiftZ" 1v&!%9       op.val1 = taq _Q:z -si       op.parent = parID 7"eK<qJ       AddOperation eID, op s(py7{ ^K       Print "Set aqueous humor thickness = " & taq-0.55 )bM,>x   N]FRL\K       '************************************************************************* Muwlehuq       'Radius and conic constant of anterior lens 4T3Z9KD!8       '************************************************************************* XQ~Xls%]        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Q z(n41@`       GetConic eID, entity, curv, conic N.mRay,   jyD~ER}J       SetConic eID, entity, 1/Rant, CCant Ma!       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant * WV=Xp   J4ZHE\       '************************************************************************* R?u(aY)P       'Radius and conic constant of posterior lens X$KTsG*       '************************************************************************* a4UwhbH       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) q\@_L.tc[       GetConic eID, entity, curv, conic &|Wqzdo?#   frUs'j/bZ       SetConic eID, entity, 1/Rpost, CCpost i&m_G5u88       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost cFc(HADM`r   e".=E;o`       '************************************************************************* ,c"J[$i$       'Lens thickness (Position of posterior lens surface) /e"iYF       '************************************************************************* ~1;M4K   @'>RGaPV       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0GxJja   /-v ;       ' Delete any z-shift(s) FD[*Q2fU       count = 0 -$"$r ~ad       While GetOperationCount(eID)>count Nl[&rZ-&           GetOperation eID, count, op >3p~>;9sc           If op.Type="ShiftZ" Then pl%!AY'oE>               DeleteOperation eID,count <Q(E {c3"               count=count-1 tTBDb           End If V?dwTc           count=count+1 Zb2pZhkW       Wend s.p> ?U   O )`L( x       'Set new z-shift Xk.OyQ@       op.Type = "ShiftZ" )T"Aji-hy       op.val1 = tlens u `/V1       op.parent = parID EF!J#N2       AddOperation eID, op 9;Z{++z       Print "Set lens thickness = " & tlens Ea S[W?u}   N `:MF 9       '************************************************************************* k Nc-@B       'Lens index of refraction Hy4;i^Ik <       '************************************************************************* Xuu&`U~%       eID = FindMaterial( "Lens" ) &V1d"";SZ       GetModelMaterial eID, mat la<.B^   [3bPoAr\       mat.Nd = nlens C]2-V1,ZX       SetModelMaterial eID, mat x)=l4A\       Print "Set lens index of refraction = " & nlens [ne51F5_   @=l6zd@       '************************************************************************* M>Q ZN       'Pupil diameter (Ff}Y.4       '************************************************************************* ~2\Sn-`       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) d7](fw@c   Q k}RcP       'Adjust pupil diameter (trimming volume inner hole) VIdKe&,   pC:YT/J       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" iS,l   U2m#BMV       ' Adjust pupil location to just in front of the lens N$kxf       parID = FindFullName( "Geometry.Arizona Eye" ) lXTE#,XVf       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) C0[U}Y/r2       count = 0 Qu[QcB{ro-       While GetOperationCount(eID)>count z |llf7:           GetOperation eID, count, op Xi%Og \vm5           If op.Type="ShiftZ" Then cy.r/Z}               DeleteOperation eID,count }P?e31@:               count=count-1 g>h/|bw4           End If @U8u6JNK'           count=count+1 \1G'{#Q       Wend '>t&fzD0       op.Type = "ShiftZ" &PE%tm       op.val1 = taq-0.01 Rm=p}       op.parent = parID =gI41Y]       AddOperation eID, op OiQf=Uz\   I+H~ 5zq.       Print "Set pupil diameter = " & pupilDiam p p"#pl   is8i_FoD,n       'Update AZ Eye subassembly Description k5E2{&wZ       eID = FindFullName( "Geometry.Arizona Eye" ) Qwpni^D8j       GetEntity eID, entity SPE)db3       entity.Description = "Accommodation = " & A & "D" <z \SKR[       SetEntity eID, entity ]Z5m_-I   y#B=9Ri=z       Update `;Tf_6c       Print "DONE!" QO}~"lMj        ^+D/59I   End Sub 4+q,[m-$(   'Wnh1|z   如果屈光度是4，光瞳直径是4，则会输出如下数据： %CHw+wT&   ~Pw9[ycn3   Accommodation = 4 Diopters S?b&4\:   Pupil Diameter = 4 mm 2>9\o]ac4   Set aqueous humor thickness = 2.81 N_NN0   Set anterior lens radius = 10.4 and conic constant = -2.375869 Y M:9m)   Set posterior lens radius = -4.424557 and conic constant = -3.081019 `B@eeXa;u   Set lens thickness = 3.927 rQ{|0+l   Set lens index of refraction = 1.42672 kVQm|frUz   Set pupil diameter = 4 Lbrl CB+   DONE!

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