Arizona眼睛模型

zy4AFW   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。 +,7dj:0S   a*CP1@O   模型 9:A>a3KOH   %cO;{og M   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。 # j*$ `W;   Table 1. AZ眼睛模型的定义 [V{JuG;s   7GfgW02   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. ,oIZ5u{#,   ^j';4'   光源 \l{*1lQ`   (y^oGY;   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。 *x`z5_yfO   8Nxf2i5   图1. 光源和提示信息使用 J[YA1   Y+iC/pd   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。 D[7K2G+   VbM5]UT/   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-A^9AAPm   图2. 字母F光源的设定方法光 s6Bt)8A   5h1!E   图3. 字母F在视网膜上位置点列图 BArsj   \qQ5x   视网膜的散射 vKAHf;1   oHI~-{m3)   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。 2P$lXGjh   r{)d?Ho=   图4. 视网膜朗伯散射设定 Yp 6;Y7^   qS&PMQ"$   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。 |{PQ0DS   >1pD'UZIy7   图5. 视网膜重点采样规格设定 34YYw@?}Y   D> Z>4:EM   脚本 n8[sR;r5f   jm RYL ("   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： Q[J,j+f<   图6. 用户对话框的创建与编辑 $@x3<}X;   图7. 用户对话框编辑器 @EO#Ms   ^Q!:0D*   如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 }S*6+4   余下的脚本计算与屈光度有关的所有参数。 {N)\It   )@eBe^   分析 t8i"f L   lUUq|Qr   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 +D?d)lK   图7. 字母F在视网膜上颜色分析 [.6>%G1C   [7<X&Q   脚本代码 &M>S$+I n   "oz@w'rG   Option Explicit     'Remove this to enable non-dimensioned variables to be used. ,Lv}Xku   (ZShhy8g   Dim entity As T_ENTITY U%oI*   Dim op As T_OPERATION 82$By]Y9   Dim mat As T_MODELMATERIAL b8b-M]P-=   Dim A As Double 4bAgbx-^   Dim pupilDiam As Double W3<O+S&   Dim eID As Long d.2b7q09   Dim parID As Long 7IK<9i4O   Dim count As Integer V2g$"W?3   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Vaha--QB   Dim tlens As Double, nlens As Double ~;+i[Z&e   Dim curv As Double, conic As Double bx6@FKns}   Dim ok As Long (R6ZoBZ   `t6lnO   Sub Main g,,cV+   \W=       '用户输入对话框 1'aS2vB9       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 _Fz)2h,3           TextBox 220,21,40,21,.TextBox1 'default: 0 I]k'0LG*^           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 *r-Bt1           OKButton 40,91,90,21 ]G1j\wnF           CancelButton 190,91,90,21 n|,Es!8:o           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Bs##3{ylu           TextBox 220,49,40,21,.TextBox2 'default: 4 dtF6IdAf       End Dialog yLDHJ}R       Dim dlg As UserDialog RLKO0 #   dtg Ja_       ok = Dialog (dlg) ..~{cU4Tt   aLsGden|       If ok=0 Then    'cancel button was pressed vi5~Rd`           Print "Execution cancelled." spl*[ d           End s &.Z;X       End If qL'3MY.!   0I#<-9&d-       'Assign accommodation and pupil diameter & use defaults if field left empty PN.6BJvu       If dlg.TextBox1 = "" Then 3zl!x           A = 0           'Default accommodation 61mQJHl.       Else 8p5'}Lq           A = CDbl(dlg.TextBox1) iEU(1?m2-       End If Q1jyetk~I   >^Y9p~       If dlg.TextBox2 = "" Then >)N#n`           pupilDiam = 4   'Default pupil diameter 78.sf{I       Else ,88Y1|:X           pupilDiam = CDbl(dlg.TextBox2) @?1%*/       End If zu^ AkMc   ':>B%k       Print " " *jJ62-o       Print "Accommodation = " & A & " Diopters" H!Od.$ZIX       Print "Pupil Diameter = " & pupilDiam & " mm" NNf CJ|   v4v+;[a%       ' Calculate new parameters with accommodation ~Fx[YPO,       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness uZYeru"w   S1B /ClKWq       Rant = 12.0 - 0.4*A                     'Radius of anterior lens {c J6Lq&       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens %b*%'#iK   9.@(&       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 3jI.!xD`       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens NRl"!FSD;"   D3K`b4YV       tlens = 3.767 + 0.04*A                  'Lens thickness hD,-!R   ,S5#Kka~a       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 1y@-   ?UxY4m%R;       'Adjust parameters to account for accommodation T9$U./69-L   9F-k:hD |       '************************************************************************* h49Q2`       'Aqueous thickness (Position of Lens) ;C vGIp&y       '************************************************************************* \8$`:3,@       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ) s8r(.W       GetCustomElement eID, entity [_0g^(`   F9<OKcXH       parID = FindFullName( "Geometry.Arizona Eye" ) 7*5ctc!dG   dL \8^L       ' Delete any shift(s) in z {L=[1       count = 0 x3P@AC$\       While GetOperationCount(eID)>count 3(&.[o Z           GetOperation eID, count, op 4sAshrUf           If op.Type="ShiftZ" Then "5YdmBy               DeleteOperation eID,count }ot _k-               count=count-1 $W?XxgkB?           End If |. 6@-h~8           count=count+1 (LfVa`<1       Wend ep?0@5D}]   m7"f6zSo(       'Set new shift in }-vBRY       op.Type = "ShiftZ" gfYB|VyWo       op.val1 = taq _R<HC       op.parent = parID 42u\Y_^ID       AddOperation eID, op IBqY$K+l       Print "Set aqueous humor thickness = " & taq-0.55 Dr1F|[   HZm i?       '************************************************************************* A1q^E(}O       'Radius and conic constant of anterior lens 3w E8y&       '************************************************************************* `#f=&S?k       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ^55?VQB       GetConic eID, entity, curv, conic /kz&9FM   _E;Y ~I,i       SetConic eID, entity, 1/Rant, CCant hkJZqUA       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant <C77_t   W,~1KUTc       '************************************************************************* ~D5MAEazS       'Radius and conic constant of posterior lens #H`y1zm       '************************************************************************* a%!XLyq       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) [Mz;:/       GetConic eID, entity, curv, conic s]c$]&IGG   C6w{"[Wv=X       SetConic eID, entity, 1/Rpost, CCpost }#8uXA       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost #+ '@/5{n   e{;e       '************************************************************************* $at|1+bQ       'Lens thickness (Position of posterior lens surface) F29AjW86       '************************************************************************* ^rwSbM$   e_], O_Z       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 2[po~}2-0   QZr<=}       ' Delete any z-shift(s) mPin\-I       count = 0 a1SOC=.M ;       While GetOperationCount(eID)>count k_>{"Rc           GetOperation eID, count, op m;f?}z_\$           If op.Type="ShiftZ" Then 14!J\`rI               DeleteOperation eID,count "6yiQ\`J               count=count-1 #&83;uys           End If %>2t=)T           count=count+1 <y!r~?       Wend fR4l4 GU?)   &.hRVW(       'Set new z-shift suFOc       op.Type = "ShiftZ" io7U[#       op.val1 = tlens #<Nvy9       op.parent = parID i@5%d!J       AddOperation eID, op %uVJLz       Print "Set lens thickness = " & tlens ==1/N{{R   I&8SP$S>J       '************************************************************************* *\KvcRMGUa       'Lens index of refraction 1\*B.       '************************************************************************* xsDa!       eID = FindMaterial( "Lens" ) -!,]Y10       GetModelMaterial eID, mat _F@p53WE   :ZS8Zm"       mat.Nd = nlens G.nftp(*}       SetModelMaterial eID, mat nFnF_       Print "Set lens index of refraction = " & nlens 1L8ULxi_?]   d[e:}1       '************************************************************************* @ :+n6       'Pupil diameter KV}U{s+U8       '************************************************************************* ;K\N       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) eM=)>zl   @gSFvb bc       'Adjust pupil diameter (trimming volume inner hole) ^[}0&_L w   _~ZQ b       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" b2X'AHK S   R P:F<`DB|       ' Adjust pupil location to just in front of the lens ?h)3S7       parID = FindFullName( "Geometry.Arizona Eye" ) &U$8zn~[k       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 9id~NNr7       count = 0 QHs:=i~VH       While GetOperationCount(eID)>count x*&&?nV Iz           GetOperation eID, count, op ?ey&Un"           If op.Type="ShiftZ" Then &lPBqw               DeleteOperation eID,count ]Uu(OI<)               count=count-1  n22hVw           End If Mj B<\g>           count=count+1 i\Pr3 7 "       Wend .aismc`=       op.Type = "ShiftZ" >}DjHLTW\       op.val1 = taq-0.01 KtUGI.X       op.parent = parID '+!S|U,{       AddOperation eID, op  q"+ q   nKjeH@&#       Print "Set pupil diameter = " & pupilDiam 1%hM8:)i_   #i+P(xV       'Update AZ Eye subassembly Description <a+eF}*2       eID = FindFullName( "Geometry.Arizona Eye" ) +# RlX3P       GetEntity eID, entity N=Uc=I7C       entity.Description = "Accommodation = " & A & "D" &@W4^-9       SetEntity eID, entity E]H    1(?CNW[       Update W?^8/1U       Print "DONE!" ]~\SR0        -?aw^du   End Sub ci,o8 [Y   fmnRUN=   如果屈光度是4，光瞳直径是4，则会输出如下数据： t?9;cS4   BK(pJNBh   Accommodation = 4 Diopters A&|Wvb=   Pupil Diameter = 4 mm qX p,d   Set aqueous humor thickness = 2.81 =nvAOvP{?   Set anterior lens radius = 10.4 and conic constant = -2.375869 Q.9Ph ~   Set posterior lens radius = -4.424557 and conic constant = -3.081019 +e0dV_T_>   Set lens thickness = 3.927 5:l*Ib:s7   Set lens index of refraction = 1.42672 EtR@sJ<   Set pupil diameter = 4 xxLgC;>[   DONE!

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