Arizona眼睛模型

K&P{2Hndr   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。 t-|=weNy   /wRK[i   模型 qD>Y}Z!   ^{sI'l~   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。 \,IDLXqp   Table 1. AZ眼睛模型的定义 4.kkxQR7r   K|J#/   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. !=Vh2UbC3   }d*sWSPu(   光源 ~x^+OXf!^g   _G8y9!J   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。 Ko1?jPE   :tDGNz*zG   图1. 光源和提示信息使用 :IKp7BS   {ZYCnS&?CL   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。 {Ll8@'5   ]~<T` )Hi   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。 (L   图2. 字母F光源的设定方法光 *oJ>4S   +CHO0n   图3. 字母F在视网膜上位置点列图 _ ~$0cj<   OZ]3OL,   视网膜的散射 e5\1k#@   l:C0:m%   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 LZbHK.G=   (#Kvm   图4. 视网膜朗伯散射设定 Xwq2;Bq   'eXw`kw(   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 :[?o7%"   IIEU{},}z   图5. 视网膜重点采样规格设定 .Zz7LG{   EHM 7=|#   脚本 zi 14]FWo   ,<WykeC   内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： !7kOw65+0   图6. 用户对话框的创建与编辑 qO'5*d;!d   图7. 用户对话框编辑器 Y]Nab0R &   /9#jv]C:   如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 _C#()#   余下的脚本计算与屈光度有关的所有参数。 Jg6[/7*m   ~PvzUT-^   分析 6$;)CO!h   kqB00 ;   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 g2_df3Q   图7. 字母F在视网膜上颜色分析  } R6h   !|QeYGnq6   脚本代码 [uV/ Ra*g   w~-d4MNM   Option Explicit     'Remove this to enable non-dimensioned variables to be used. wi >ta   };sm8P {M   Dim entity As T_ENTITY TzXl ?N   Dim op As T_OPERATION _$lQK{@rY   Dim mat As T_MODELMATERIAL k&;L(D   Dim A As Double fJV VW   Dim pupilDiam As Double Vjd =F.V+   Dim eID As Long &y?B&4|hM   Dim parID As Long nuA!Jln_   Dim count As Integer e5]0<s$   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double uV:;y}T^Z   Dim tlens As Double, nlens As Double q|2C>{8   Dim curv As Double, conic As Double /L Tyiiz6   Dim ok As Long #nhAW   %Qb r Vl+   Sub Main m"}G-#   (#Aq*2Z.       '用户输入对话框 U.x.gZRo[       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 0:8'Ov(           TextBox 220,21,40,21,.TextBox1 'default: 0 Ut=y`]F           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 (*gpa:Sc           OKButton 40,91,90,21 p}z0(lQ*~           CancelButton 190,91,90,21 F,:VL*.5kJ           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 "YZ`g}sG           TextBox 220,49,40,21,.TextBox2 'default: 4 0w]?yqn E       End Dialog }@4*0_g"Aw       Dim dlg As UserDialog V [>5   `9gx-')]\       ok = Dialog (dlg) _Pal)re]U   ']D( ({%g       If ok=0 Then    'cancel button was pressed vt,X:3           Print "Execution cancelled." hn.fX:}           End w{IqzmPiH       End If =;T[2:JUu   _,Y79 b6       'Assign accommodation and pupil diameter & use defaults if field left empty "bH ~CG:Y       If dlg.TextBox1 = "" Then z{x -Vfd           A = 0           'Default accommodation mt'#j"mU       Else V5MbWXgR           A = CDbl(dlg.TextBox1) *PPFk.#x       End If f*Bc`+G   #>'0C6Xn       If dlg.TextBox2 = "" Then i/Z5/( zF           pupilDiam = 4   'Default pupil diameter v\C+G[MV7       Else *<1m 2t>.           pupilDiam = CDbl(dlg.TextBox2) |Gi/=[Tp       End If qE[}Cf]X   $mlcaH       Print " " KhvCkQMI@       Print "Accommodation = " & A & " Diopters" %94"e7Hy       Print "Pupil Diameter = " & pupilDiam & " mm" LTHS&3%2   i%2K%5{)$D       ' Calculate new parameters with accommodation fkM4u<R^       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness *XuzTGa"   lki(_@3       Rant = 12.0 - 0.4*A                     'Radius of anterior lens e{=$4F       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens aHw VoT   DS yE        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 3L|k3 `I4       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens s0SB!-Vjm   B!0[LlF+       tlens = 3.767 + 0.04*A                  'Lens thickness t{9Ph]e   QHK$       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction y5I7pbe   ,bJx| K       'Adjust parameters to account for accommodation Sk-Ti\   bmLNR       '************************************************************************* Qi M>59[       'Aqueous thickness (Position of Lens) Up:#Zs2       '************************************************************************* Sl1N V       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) I g`#U~       GetCustomElement eID, entity ^]HwStn&=   vs+N{ V       parID = FindFullName( "Geometry.Arizona Eye" ) 0#G"{M   M6>l%[       ' Delete any shift(s) in z i~4Kek6,I       count = 0 -kO=pYP*O       While GetOperationCount(eID)>count w jF\>           GetOperation eID, count, op U4 gZW]F           If op.Type="ShiftZ" Then {|cA[#j#               DeleteOperation eID,count =S,^"D\Z:               count=count-1 KE_Ze\P           End If Ua4} dW[w           count=count+1 r?$\`,;       Wend |kn}iA@72p   ;8!D8o(+       'Set new shift in <mxUgU       op.Type = "ShiftZ" ?~$y3<[       op.val1 = taq <]<50       op.parent = parID pP .        AddOperation eID, op -v:Y\=[\       Print "Set aqueous humor thickness = " & taq-0.55 /cg!Ap5    {VFpfo       '************************************************************************* ,xiRP$hGhh       'Radius and conic constant of anterior lens OA8pao~H       '************************************************************************* wGB'c's*       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) nv={.H       GetConic eID, entity, curv, conic W{%M+a[#l   tC;D4i       SetConic eID, entity, 1/Rant, CCant eu~;G H       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant T@L ^RaPX   ',.Xn`c       '************************************************************************* 4#o` -vcW       'Radius and conic constant of posterior lens fRbVc       '************************************************************************* Y=5hm       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) R75sK(oS       GetConic eID, entity, curv, conic 4B|f}7%\   Xd4~N:       SetConic eID, entity, 1/Rpost, CCpost tlW}lN}       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Gce![<|ph   zd}"8       '************************************************************************* dCinbAQ       'Lens thickness (Position of posterior lens surface) _|F h^hq       '************************************************************************* zUOYH4+   iaMZ37       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) f}fM%0/5   *2[r?!       ' Delete any z-shift(s) Dx8^V %b       count = 0 4"GY0) Q       While GetOperationCount(eID)>count x[_+U4-/           GetOperation eID, count, op /rquI y^           If op.Type="ShiftZ" Then myPo&"_ x               DeleteOperation eID,count D;Z\GnD               count=count-1 "Aynt_a.           End If H6L`239u           count=count+1 ZqSczS7uf       Wend Alrk3I3{   P: Bg ()       'Set new z-shift XX+4X*(o       op.Type = "ShiftZ" c+q4sNnE       op.val1 = tlens s01n[jQ       op.parent = parID # TvY*D,       AddOperation eID, op gI[xOK#       Print "Set lens thickness = " & tlens -&+[/   ?8`b       '************************************************************************* >2%!=q3)       'Lens index of refraction D&.+Dx^G       '************************************************************************* y3d`$'7H>       eID = FindMaterial( "Lens" ) m'Ran3rp       GetModelMaterial eID, mat O Qd,.m   Z/O5Dear/h       mat.Nd = nlens aK'BC>uFI       SetModelMaterial eID, mat p2\@E} z       Print "Set lens index of refraction = " & nlens y<kW2<?   orJN#0v4       '************************************************************************* E-CZk_K9       'Pupil diameter >]FRHJo_       '************************************************************************* K1jE_]@Z       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) BjSLbw-C   Uh{|@D       'Adjust pupil diameter (trimming volume inner hole) kid@*.I   \:8 >@Q       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" L)kwMk   I_\j05       ' Adjust pupil location to just in front of the lens | X! d*4       parID = FindFullName( "Geometry.Arizona Eye" ) :W^ k3/t       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ca5Ir<mL       count = 0 !ouJ3Jn        While GetOperationCount(eID)>count ht)J#Di           GetOperation eID, count, op +hGr2%*0f           If op.Type="ShiftZ" Then z]K:Amp;Z               DeleteOperation eID,count 'V/+v#V+>               count=count-1 T=%,^           End If DYx3NDX7           count=count+1 #R}sGT       Wend O,u$L       op.Type = "ShiftZ" :A"GOc,       op.val1 = taq-0.01 zr2oU '+       op.parent = parID M] 7#       AddOperation eID, op kocgPO5   ,:;ZzHzR0       Print "Set pupil diameter = " & pupilDiam g{RVxGE7   .]24V!J(1w       'Update AZ Eye subassembly Description ;Lr]w8d       eID = FindFullName( "Geometry.Arizona Eye" ) Y'H|Tk^`       GetEntity eID, entity opc`n}Fc       entity.Description = "Accommodation = " & A & "D" },+ &y^       SetEntity eID, entity -Q9} gaH_   /6 QwV->       Update jnho*,X       Print "DONE!" q 8#zv_>K        4d-f6iiFV   End Sub `|(S]xPHM   /fv;`?~d*   如果屈光度是4，光瞳直径是4，则会输出如下数据： mQUI9   C%H{"   Accommodation = 4 Diopters }LeizbU   Pupil Diameter = 4 mm a]\l: r   Set aqueous humor thickness = 2.81 m) QV2n   Set anterior lens radius = 10.4 and conic constant = -2.375869 ~HBQQt   Set posterior lens radius = -4.424557 and conic constant = -3.081019 %\$~B?At   Set lens thickness = 3.927 %?2y2O,;   Set lens index of refraction = 1.42672 0i[v,eS   Set pupil diameter = 4 #83`T&Xw*   DONE!

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