Arizona眼睛模型

/cT6X]o8   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。 C\4d.~C:w3   >gDeuye   模型 V!l?FOSZ   [bw1!X3   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。 (eAz nTU   Table 1. AZ眼睛模型的定义 +NbiUCMX   67XUhnE   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. w{ ;Sp?Os   EJ(36h   光源 @lWYc`>}   5'(T*"   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。 `~z[Hj=2   1_};!5$.   图1. 光源和提示信息使用 et"Pb_-U   u=tp80_   除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 2Z5_@Y   !nq`PyMR   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 Si@6'sw   图2. 字母F光源的设定方法光 \t5_V)P   w3z'ZCcr;"   图3. 字母F在视网膜上位置点列图 Npi)R)   *nYg-)   视网膜的散射 3-&~jm~"   zk"8mTg   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 !FDd5CS   P*H0Hwn;   图4. 视网膜朗伯散射设定 *AP"[W   IJt'[&D   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 &_u.q/~   ^Ua6.RH8   图5. 视网膜重点采样规格设定 l4dG=x}M]   ,@/O\fit)   脚本 K8Q3~bMf   S~hu(x#   内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： fERO( o   图6. 用户对话框的创建与编辑 Ctn 4q'Q   图7. 用户对话框编辑器 wZN_YFwQ   .xuzu#-   如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 !l=)$RJKdD   余下的脚本计算与屈光度有关的所有参数。 9K#3JyW*   -cijLlz%+   分析 e#,(a   # UhH   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 $d Xx@6fP   图7. 字母F在视网膜上颜色分析 hlDB'8   q2s 0g*z   脚本代码 d,?Tq   nJGs,~"   Option Explicit     'Remove this to enable non-dimensioned variables to be used. 1]eRragm"   N'WC!K.e   Dim entity As T_ENTITY vg5_@7   Dim op As T_OPERATION ]ly" K!1,   Dim mat As T_MODELMATERIAL tv.<pP9-C   Dim A As Double aWlIq(dU   Dim pupilDiam As Double dJ m9''T')   Dim eID As Long bc4V&   Dim parID As Long 8I*N   Dim count As Integer 8*@{}O##   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double fggs ;Le   Dim tlens As Double, nlens As Double KyfH8Na?   Dim curv As Double, conic As Double W>i"p~!   Dim ok As Long o.Rv<a5.L   &e@)yVLL   Sub Main 9$Z0mzk   9aY8`B       '用户输入对话框  u\L}B!       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 RG""/x;           TextBox 220,21,40,21,.TextBox1 'default: 0 ,!b<SQ5M           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 BjsT 9?6W/           OKButton 40,91,90,21 ~bxev/$d           CancelButton 190,91,90,21 [#q]B=JB           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 I](a 5i           TextBox 220,49,40,21,.TextBox2 'default: 4 )?UoF&c /       End Dialog 8"9&x} tl-       Dim dlg As UserDialog /De~K+w7o   #}FUau$       ok = Dialog (dlg) z__?kY   3>-h- cpMX       If ok=0 Then    'cancel button was pressed Tk4>Jb           Print "Execution cancelled." "mf$E|           End )\= xPfs       End If L;%w{,Ji   *k}m?;esb       'Assign accommodation and pupil diameter & use defaults if field left empty (pd$?vRy       If dlg.TextBox1 = "" Then (+epRC           A = 0           'Default accommodation robg1       Else lQHF=Jex           A = CDbl(dlg.TextBox1) ^]nLE]M       End If  ]|.ked   9+^)?JUYll       If dlg.TextBox2 = "" Then xBVOIc[4(           pupilDiam = 4   'Default pupil diameter 3WJk04r       Else ERV]N:(           pupilDiam = CDbl(dlg.TextBox2) d@$|zr6       End If $M 8&&M   'R79,)|;[       Print " " eKvr1m- -       Print "Accommodation = " & A & " Diopters" GDL/5m#       Print "Pupil Diameter = " & pupilDiam & " mm" vKG\8+   ],pB:=       ' Calculate new parameters with accommodation p )yP_P       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 1N8] ~j   lD 0-S0i       Rant = 12.0 - 0.4*A                     'Radius of anterior lens 0%rDDB       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens i D IY|   q()o|V       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens /GIGE##1F       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens UhDQl%&He   #T_!-;(Z       tlens = 3.767 + 0.04*A                  'Lens thickness Uz^N6q   (@+pz/       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction $72eHdy/yl   @-!P1]V|       'Adjust parameters to account for accommodation )=[\YfK   )t|:_Z       '************************************************************************* 1'E=R0`pA       'Aqueous thickness (Position of Lens) _YF>Y=D-       '************************************************************************* 4H-eFs%5       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) L@S\ rImw       GetCustomElement eID, entity u?Ffqt9'   ?}cmES kX@       parID = FindFullName( "Geometry.Arizona Eye" ) .`OU\LA   M*zpl}       ' Delete any shift(s) in z +#FqC/`l       count = 0 5~[7|Y       While GetOperationCount(eID)>count m^3x% ENZ           GetOperation eID, count, op eJ?o z^           If op.Type="ShiftZ" Then ZbYC3_7w               DeleteOperation eID,count r N$0qo               count=count-1 ]].~/kC^3k           End If 4E^ ?}_$           count=count+1 v1OVrk>s>       Wend >3uNh:|>/   |U|>YA1[b       'Set new shift in C t,p       op.Type = "ShiftZ" .Fo#Dmq3       op.val1 = taq VHD+NY/       op.parent = parID QRQZ{m       AddOperation eID, op )zr*Ecz       Print "Set aqueous humor thickness = " & taq-0.55 {rKC4:   ..)J6L5l       '************************************************************************* >@2<^&K`       'Radius and conic constant of anterior lens HOP*QX8C%       '************************************************************************* T8o](:B~       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) xe!bfzU       GetConic eID, entity, curv, conic q?}C`5%D   #r'MfTr       SetConic eID, entity, 1/Rant, CCant FiUQ2w4       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ?\V#^q-   cpdESc9W       '************************************************************************* S<0 &V       'Radius and conic constant of posterior lens Tv=lr6t8       '************************************************************************* V]zc-gYI       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) )5}<@Ql       GetConic eID, entity, curv, conic PQ&*(G   *S,~zOYN       SetConic eID, entity, 1/Rpost, CCpost ix!xLm9\       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Hl$W+e|tj   <V&0GAZ       '************************************************************************* AP&//b,^M       'Lens thickness (Position of posterior lens surface) {kpF etXt?       '************************************************************************* *ub2dH4/   2&1mI>:F       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ot}erC2~   {MgRi7       ' Delete any z-shift(s) Q~,Mzt"}W       count = 0 up5f]:!       While GetOperationCount(eID)>count p!UR;xHI\           GetOperation eID, count, op P 45Ir ir           If op.Type="ShiftZ" Then |:eTo<               DeleteOperation eID,count ? :H+j6+f               count=count-1 4aXIRu%#7           End If &QHJ%c           count=count+1 ~5KcbGD~       Wend gm9*z.S\'   Uy?jVPL       'Set new z-shift E%mEfj7       op.Type = "ShiftZ" Q-<]'E#\(       op.val1 = tlens l2 .S^S       op.parent = parID LF7-??'       AddOperation eID, op _;HdX$op       Print "Set lens thickness = " & tlens $.`o   @:>"VP<(       '************************************************************************* ,Z{\YAh1       'Lens index of refraction T fLqxioqZ       '************************************************************************* 4XpWDfa.}       eID = FindMaterial( "Lens" ) 2"ax*MQH<^       GetModelMaterial eID, mat <],{at` v   cH5i420;aO       mat.Nd = nlens I6.rN\%b       SetModelMaterial eID, mat 6K.2VY#       Print "Set lens index of refraction = " & nlens `zQuhD 8W   ^')8-aF .       '************************************************************************* N5?bflY       'Pupil diameter <[dcIw<7       '************************************************************************* }5 rR^ryA       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 2zC4nF)>O   iWCYK7c@.-       'Adjust pupil diameter (trimming volume inner hole) bmG`:_   (:l6R9'=       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" FV^jCseZ   Q#g`D,:o%~       ' Adjust pupil location to just in front of the lens ^j}C]cq{Xg       parID = FindFullName( "Geometry.Arizona Eye" ) 6W i n!4       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ZM<6yj"f       count = 0 Hx.|5n,5       While GetOperationCount(eID)>count F[ E'R.:           GetOperation eID, count, op JxVGzb `8           If op.Type="ShiftZ" Then SzW;Yb"#^k               DeleteOperation eID,count /oPW0of               count=count-1 Hv;xaT<}V           End If u^2`$W           count=count+1 # -'A =j       Wend khy'Y&\F;       op.Type = "ShiftZ" ob7'''i       op.val1 = taq-0.01 @|Pm%K`1       op.parent = parID 'cO8& |       AddOperation eID, op [:X@|,1V!L   Olzw)Wj G       Print "Set pupil diameter = " & pupilDiam kvbZx{s   nb_/1{F       'Update AZ Eye subassembly Description qk& F>6<9*       eID = FindFullName( "Geometry.Arizona Eye" ) v-8>@s jy8       GetEntity eID, entity _pdKcE\X       entity.Description = "Accommodation = " & A & "D" @ m`C%7<       SetEntity eID, entity L.;b(bFe   Myc-lCE       Update h#0n2o#       Print "DONE!" vXKL<        tD8fSV   End Sub Y:\msq1xp   !Rv ;~f/2   如果屈光度是4，光瞳直径是4，则会输出如下数据： :2/L1A)O   YIe1AF}    Accommodation = 4 Diopters gPMR,TU   Pupil Diameter = 4 mm IyO0~Vx>   Set aqueous humor thickness = 2.81 ?m)<kY   Set anterior lens radius = 10.4 and conic constant = -2.375869 fJ}e   Set posterior lens radius = -4.424557 and conic constant = -3.081019 +<E#_)}`D6   Set lens thickness = 3.927 cK$yr)7   Set lens index of refraction = 1.42672 m H:Un{,   Set pupil diameter = 4 -zK>{)Z=q   DONE!

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