Arizona眼睛模型

pZl t4   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。 UKV<Ye|   nw,.I [   模型 /$]S'[5uF   +N7<[hE;   模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 <8Tp]1z   Table 1. AZ眼睛模型的定义 esE!i0%   &-p~UZy   在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. d>W#c8X>   .-![ ra   光源 y N9~/g   (n~fe-?}8   多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 qV idtSb   /W-ges   图1. 光源和提示信息使用 rQGInzYp   <#57q%   除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 r&B0-7r   b_6c K#   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 t 4zUj%F   图2. 字母F光源的设定方法光 +boL?Ix+    f+!J1   图3. 字母F在视网膜上位置点列图 X>Q44FV!   'J-a2oiM(   视网膜的散射 l0URJRK{*   "S6";G^I   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 n1JV)4Mv   .9=4Af   图4. 视网膜朗伯散射设定 K1A<m=If   V*fv>f:Yv   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 Vy[xu$y   \P9ms?((A   图5. 视网膜重点采样规格设定 1n}#54   53ZbtEwhwr   脚本 #Y3-P   8!!h6dQgI   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： 3{t[>O;   图6. 用户对话框的创建与编辑 G~bDl:k`A   图7. 用户对话框编辑器 iu*&Jz)D>   H25Qx;(dTk   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。 RXcN<Y&   余下的脚本计算与屈光度有关的所有参数。 U{Oo@ztT   <%%)C>l   分析 ma@V>*u   [kqtkgK$j2   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 }2e s"   图7. 字母F在视网膜上颜色分析 iymN|KdpaZ   Y/I)ECm   脚本代码 %xG <hNw/   |ka/5o   Option Explicit     'Remove this to enable non-dimensioned variables to be used. t2OBVzK   b Hx@   Dim entity As T_ENTITY |39,n~"o&   Dim op As T_OPERATION 7)[Ve1;/N   Dim mat As T_MODELMATERIAL `[#id@ Z1   Dim A As Double 7}~w9jK"F   Dim pupilDiam As Double [ wm0a4fg   Dim eID As Long ;L-)$Dy4   Dim parID As Long PX/{!_mM   Dim count As Integer }0]u A|lH*   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double na~ FT[3C   Dim tlens As Double, nlens As Double N6u>V~i   Dim curv As Double, conic As Double _6,\;"it?8   Dim ok As Long # -f9> S9_   ~&RrlFh   Sub Main G'}N?8s1   >K4Nn(~ys       '用户输入对话框 `o }+2Cb       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 .*9u_2<           TextBox 220,21,40,21,.TextBox1 'default: 0 52Lp_ M           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 l5VRdZ4Uf           OKButton 40,91,90,21 46e? %0(           CancelButton 190,91,90,21 dm=?o           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 uQx/o^           TextBox 220,49,40,21,.TextBox2 'default: 4 ||wi4TP       End Dialog Nj2l>[L;       Dim dlg As UserDialog =fnBE`Uc   <dD!_S6@,       ok = Dialog (dlg) r5nHYV&7   -2[4 @       If ok=0 Then    'cancel button was pressed 6. KEe^[-           Print "Execution cancelled." ]ilLed           End - QY<o|       End If 1|xe'w{   _z BfNz9D       'Assign accommodation and pupil diameter & use defaults if field left empty Udtz zka       If dlg.TextBox1 = "" Then sK+uwt           A = 0           'Default accommodation T!y 9v5       Else W3>9GY90R           A = CDbl(dlg.TextBox1) $6*Yh-"g       End If _L~ 3h   fvH{va.       If dlg.TextBox2 = "" Then 612,J           pupilDiam = 4   'Default pupil diameter B&rNgG7~       Else %}zkmEY.e           pupilDiam = CDbl(dlg.TextBox2) .0xk},       End If .$}z</#!   2/V%jS[4#y       Print " " ?G',Qtz<K       Print "Accommodation = " & A & " Diopters" y3 N[F       Print "Pupil Diameter = " & pupilDiam & " mm" x X3I`   /"k[T       ' Calculate new parameters with accommodation g3[-[G ^5       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness @SxZ>|r-|v   8+gp"!E       Rant = 12.0 - 0.4*A                     'Radius of anterior lens ^VMCs/g6       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens u4xtlGt5   >}~[ew       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ;K8}Yq9p9       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens A~nqSe   H^S<bZ       tlens = 3.767 + 0.04*A                  'Lens thickness }`QZV_    l]wLQqoO       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 8[X"XThj   tR<#CCtRp'       'Adjust parameters to account for accommodation Km= Y^x0   /LWk>[ Z;       '************************************************************************* 3$YbEl@#       'Aqueous thickness (Position of Lens) "k@[7 7       '************************************************************************* e/+.^ '{       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5;/q[oXI       GetCustomElement eID, entity Os>&:{D4!   nF]R"       parID = FindFullName( "Geometry.Arizona Eye" ) N.z2eo   S WTZ6(!oW       ' Delete any shift(s) in z q#c+%,Z=C       count = 0 4<UAT|L^`       While GetOperationCount(eID)>count 5ta;CG           GetOperation eID, count, op .EHq.cd e           If op.Type="ShiftZ" Then aL&egM*               DeleteOperation eID,count 9<3}zwJ               count=count-1 __tA(uA           End If k -R"e           count=count+1 j?o6>j       Wend \Q}Y"oq   "wZvr}xk       'Set new shift in QbHX .:C       op.Type = "ShiftZ" ZaY|v-       op.val1 = taq R8lja%+0$       op.parent = parID gS[B; +d       AddOperation eID, op |H^v8^%>zm       Print "Set aqueous humor thickness = " & taq-0.55 #U%HGTE0   P(@Q[XQ2       '*************************************************************************  9Ca0Tu       'Radius and conic constant of anterior lens ?nL , Otz       '************************************************************************* )mN/e+/Lu       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) aizws[C       GetConic eID, entity, curv, conic eA]8M^   ;J+iwS*Z       SetConic eID, entity, 1/Rant, CCant T&6>Eb0{       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant t`hes $E   N\tFK*U^I       '************************************************************************* ,jz~Np_2       'Radius and conic constant of posterior lens O[U`(A:       '************************************************************************* xa]yq%       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) lAo~w       GetConic eID, entity, curv, conic l{^ s4   Sw>>]UjU       SetConic eID, entity, 1/Rpost, CCpost X)RgXl{       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Io  IhQ   +UziO#D       '************************************************************************* \5<Z[#{       'Lens thickness (Position of posterior lens surface) g&w~eWpk       '************************************************************************* k&5T-\q   fsEQ4xN'       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) J{a9pr6   j7w9H/XF}       ' Delete any z-shift(s) G,<d;:       count = 0 "v0bdaQH3       While GetOperationCount(eID)>count *K?UWi#$           GetOperation eID, count, op 2x|FVp           If op.Type="ShiftZ" Then \X(*JNQ               DeleteOperation eID,count eTgtt-;VR               count=count-1 }JQy&V%           End If vY.VFEP/           count=count+1 =6\^F i       Wend JURu>-i   +{;wOQ.       'Set new z-shift $A,YQH+       op.Type = "ShiftZ" [h B$%i]\<       op.val1 = tlens /L(}VJg-       op.parent = parID 2)$-L'YS       AddOperation eID, op $Q'LDmot       Print "Set lens thickness = " & tlens "B+F6   1K|F;p       '************************************************************************* ct,;V/Dx       'Lens index of refraction ?9eiT:2       '************************************************************************* .C+(E@eyA       eID = FindMaterial( "Lens" ) )@Y< <9'2       GetModelMaterial eID, mat  yoe@]c=   >tMI%r       mat.Nd = nlens oXk6,b"       SetModelMaterial eID, mat =tA;JB       Print "Set lens index of refraction = " & nlens 0cfGI%   An?#B4:       '************************************************************************* yXEI%2~)       'Pupil diameter >Sw?F&       '************************************************************************* 6 M_ W(       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) |}YxxeAk   &ZFHWI(P       'Adjust pupil diameter (trimming volume inner hole) T?Z&\g0yp   "8?Fl&=Q       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" PC255   e87a9ZPm       ' Adjust pupil location to just in front of the lens Us#/#-hJ       parID = FindFullName( "Geometry.Arizona Eye" ) pNQ7uy       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) mv,a>Cvs[       count = 0 up8d3       While GetOperationCount(eID)>count pH3\X cn           GetOperation eID, count, op aYc<C$:NC"           If op.Type="ShiftZ" Then a\,V>}e               DeleteOperation eID,count jVoD9H F/               count=count-1 >P}XCAU           End If y|0/;SjV           count=count+1 ofz?L#:2       Wend )ryPK"V       op.Type = "ShiftZ" D ZZRu8~       op.val1 = taq-0.01 <ycR/X       op.parent = parID Xj30bt       AddOperation eID, op .tHc*Eh   sy4Nm0m       Print "Set pupil diameter = " & pupilDiam BOA7@Zaa$p   G[_Z|Xi1       'Update AZ Eye subassembly Description 8 ?y|       eID = FindFullName( "Geometry.Arizona Eye" ) `Z{s,!z       GetEntity eID, entity ~d\V>       entity.Description = "Accommodation = " & A & "D" l:/x&=w       SetEntity eID, entity rp1+K4]P   g6.I~oQj       Update &AeNrtGu       Print "DONE!" 8gt*`]I        &e*@:5Z:k   End Sub 6r@>n_6LY   DVg$rm`   如果屈光度是4，光瞳直径是4，则会输出如下数据： 4eSFpy1   $II~tO    Accommodation = 4 Diopters 7D 3-/_v   Pupil Diameter = 4 mm rADzJ#CU\   Set aqueous humor thickness = 2.81 .EjR<UU   Set anterior lens radius = 10.4 and conic constant = -2.375869 [C;Neslo   Set posterior lens radius = -4.424557 and conic constant = -3.081019 rHOhi|+   Set lens thickness = 3.927 AkO);4A;Jd   Set lens index of refraction = 1.42672 SG0PQ   Set pupil diameter = 4 SH8zkAA7u}   DONE!

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