Arizona眼睛模型

uqeWdj*Y   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。 >@e%,z   7Bd_/A($   模型 fTtSx_}3H   #UeU:RJ1   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。 I[IQFka}   Table 1. AZ眼睛模型的定义 8/$iCW   g)6 k?Y   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. >:nJTr   ddhTri'f   光源 Y6;9j=[   >mSl~.I2   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。 0=zS&xM   :@A;!'zpL   图1. 光源和提示信息使用 +NMSvu_?   0nnq/u^   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。 JN-8\L   <Py/uF|   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。 Yaepy3F   图2. 字母F光源的设定方法光 ?S:_J!vX{   iL' ]du<wk   图3. 字母F在视网膜上位置点列图 _u5U> w   dg8 \(G   视网膜的散射 'E8Qi'g   <q=B(J'   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。 r:Cid*~m   N|L5Ru    图4. 视网膜朗伯散射设定 yvwcXNXR@   [kkcV5I-   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。 5R G5uH/-<   =B%e0M   图5. 视网膜重点采样规格设定 hG3Lj7)UH   Oip..f0   脚本 >G7U7R}R   VO?NrKyeW   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： Md{f,,E'^@   图6. 用户对话框的创建与编辑 Hf|:A(vCx   图7. 用户对话框编辑器 ;KN@v5`p   9DKB+K.1   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。 r5wXuA,Um   余下的脚本计算与屈光度有关的所有参数。 nEr, jd~f    ?C\9 lLX   分析 d_B5@9e#   #+nv,?@   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 {u3u%^E;R   图7. 字母F在视网膜上颜色分析 th|Q NG   Sp:de,9@   脚本代码 ;r}<o?'RM   [wYQP6Cyy   Option Explicit     'Remove this to enable non-dimensioned variables to be used. ^Tmmx_Xw   JpiKZG@L   Dim entity As T_ENTITY .C?gnOq   Dim op As T_OPERATION FM];+d0   Dim mat As T_MODELMATERIAL &T}e93]   Dim A As Double FgaBwd^W   Dim pupilDiam As Double r6G)R+#   Dim eID As Long Q)&Ztw<   Dim parID As Long 7X>3WF   Dim count As Integer !I&Sy]G   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double sBL^NDqa2   Dim tlens As Double, nlens As Double HrxEC)V6#   Dim curv As Double, conic As Double VvKH]>*   Dim ok As Long [%:NR   7]bqs"t   Sub Main [*v\X %+   N%yFL       '用户输入对话框 d0az#Yg!       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 :{2$X|f 3           TextBox 220,21,40,21,.TextBox1 'default: 0 qsx1:Ny1           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 LJx g           OKButton 40,91,90,21 1<5yG7SZ           CancelButton 190,91,90,21 3iTjM>+>           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 o 8U2vMH           TextBox 220,49,40,21,.TextBox2 'default: 4 cPSu!u}D       End Dialog &h-1Z}       Dim dlg As UserDialog 8Qh/=Ir   In2D32"F       ok = Dialog (dlg) V>Cf 8>m   e F@E|kK       If ok=0 Then    'cancel button was pressed P 2kZi=0           Print "Execution cancelled." Ygb#U'|           End :1Cc~+]w(u       End If wd*Jq   gu!A:Q       'Assign accommodation and pupil diameter & use defaults if field left empty cjk5><}`H7       If dlg.TextBox1 = "" Then o hCPNm           A = 0           'Default accommodation H Vy^^$       Else Khl7Ez           A = CDbl(dlg.TextBox1) rYJvI       End If 5YasD6l   x4K 5       If dlg.TextBox2 = "" Then Oc>-jhx?           pupilDiam = 4   'Default pupil diameter {U9jA _XX       Else *?S\0a'W@           pupilDiam = CDbl(dlg.TextBox2) M}>q>       End If <Jx{Uv   ia[wVxd       Print " " ZpyRvDz       Print "Accommodation = " & A & " Diopters" EMo6$(       Print "Pupil Diameter = " & pupilDiam & " mm" 6~s,j({^   U&NOf;h$       ' Calculate new parameters with accommodation %j,Ny}a       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness V4>P8cE   *HRRv.iQ       Rant = 12.0 - 0.4*A                     'Radius of anterior lens Cnolka"       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens v|xlI4   WBGYk);       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens :Z)s'd.       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Smp+}-3O   c?d#Bj ?       tlens = 3.767 + 0.04*A                  'Lens thickness >,v~,<3 i   #3S/TBy,       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction  >Pu*MD;   bu.36\78       'Adjust parameters to account for accommodation 'coqm8V[%   H_Yy.yi       '************************************************************************* |Yx8Ez       'Aqueous thickness (Position of Lens) 1#V0g Q       '************************************************************************* [qz6_WOo       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 3O.-'U1K       GetCustomElement eID, entity ;WhB2/5v   L%DL n       parID = FindFullName( "Geometry.Arizona Eye" ) hug12Cu   >@X=E3       ' Delete any shift(s) in z Um~jp:6p       count = 0 s-*XAnot       While GetOperationCount(eID)>count gSC@uf           GetOperation eID, count, op 8|l Yf%n>j           If op.Type="ShiftZ" Then 3B0%:Jj               DeleteOperation eID,count buoz La               count=count-1 -'nx7wnj2           End If _YY)-H           count=count+1 }8svd#S+       Wend ,%C$~+xjM   sw&Qks?V       'Set new shift in kahv1s-       op.Type = "ShiftZ" s2E}+ #       op.val1 = taq ^ey\ c1K       op.parent = parID OV[-m;h|       AddOperation eID, op M;E&@[5       Print "Set aqueous humor thickness = " & taq-0.55 bhI8b/   I}:/v$btM       '************************************************************************* 9we=aX5       'Radius and conic constant of anterior lens 29GiNy+ob       '************************************************************************* M_e!s}F       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 1vThb       GetConic eID, entity, curv, conic ~7m+cWC-+   c*h5lM'n6       SetConic eID, entity, 1/Rant, CCant V$@2:@8mo       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant _+{s^n=   o]nQo?!       '************************************************************************* ~$@I <= L       'Radius and conic constant of posterior lens RsbrD8*AD       '************************************************************************* L+u_153       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) czp5M U_^       GetConic eID, entity, curv, conic ZGrV? @o,6   =}L[/RL       SetConic eID, entity, 1/Rpost, CCpost  LKm5U6       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost %H@fVWe2wT   :sn}D~       '************************************************************************* >3ODqRu       'Lens thickness (Position of posterior lens surface) |`|b&Rhu       '************************************************************************* Y,a.9AWw)   ":Q70*xSm       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) XH. _Z   +V) (,f1       ' Delete any z-shift(s) $lv  g.u       count = 0 B !<I[fvK       While GetOperationCount(eID)>count (]pQ.3           GetOperation eID, count, op u66w('2           If op.Type="ShiftZ" Then h$k(|/+               DeleteOperation eID,count t^YD CcvoQ               count=count-1 f ZI Swr           End If 4uv }6&R           count=count+1 !=-l760       Wend ^cY5!W.q8   .1}u0IbJ       'Set new z-shift C>;}CH|X       op.Type = "ShiftZ" [)a,rrhj       op.val1 = tlens CN >q`[!       op.parent = parID .v;Npm2       AddOperation eID, op -uh/W=Q1R       Print "Set lens thickness = " & tlens T}zi P   )FB)ZK;       '************************************************************************* PCES&|*rf       'Lens index of refraction UeVF@rw       '************************************************************************* 3B_S>0H"$       eID = FindMaterial( "Lens" ) 1rN&Y,61\       GetModelMaterial eID, mat 8-m"]o3   rg $71Ir       mat.Nd = nlens )S`A+M K]       SetModelMaterial eID, mat wCdUYgsPT"       Print "Set lens index of refraction = " & nlens wU=(_S,c   /r)d4=1E       '************************************************************************* ?GFVV->i       'Pupil diameter SVR AkP-       '************************************************************************* 'Hq}h)`       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) {!,+C0   R&-bA3w$       'Adjust pupil diameter (trimming volume inner hole) RpreW7B_Q*   a E#s#Kv        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" dx~F [   Wl*\kQ}U       ' Adjust pupil location to just in front of the lens #3qkG)       parID = FindFullName( "Geometry.Arizona Eye" ) 2Gj&7A3b       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 4iKT       count = 0 5ogbse"       While GetOperationCount(eID)>count .Wr7?'D1M           GetOperation eID, count, op ;mMn-+3<           If op.Type="ShiftZ" Then *z(.D\{%               DeleteOperation eID,count HO wJ2L               count=count-1 tvg7mU]l           End If I*0W\Qz@           count=count+1 l\S..B +       Wend 10a=[\ Q       op.Type = "ShiftZ" ?1[go+56X       op.val1 = taq-0.01 ;A|6&~E0G       op.parent = parID Z{e5 OJ       AddOperation eID, op BtjsN22   }e82e       Print "Set pupil diameter = " & pupilDiam 3GaM>w}>W   SQEXC*08       'Update AZ Eye subassembly Description ]C Tu|       eID = FindFullName( "Geometry.Arizona Eye" ) 8sL7p4       GetEntity eID, entity `]fY9ZDKs       entity.Description = "Accommodation = " & A & "D" R=E )j^<F       SetEntity eID, entity LDbo   YAO.Ccz       Update $H5Xa[       Print "DONE!" )EO$JwQ        MRiETd"   End Sub Lrz>00(*4   u|Db%) [   如果屈光度是4，光瞳直径是4，则会输出如下数据： '&U X'Dd~Q   C=.   Accommodation = 4 Diopters V+E2nJ   Pupil Diameter = 4 mm inp=-   Set aqueous humor thickness = 2.81 ($ae n   Set anterior lens radius = 10.4 and conic constant = -2.375869 2#sE\D   Set posterior lens radius = -4.424557 and conic constant = -3.081019 jtd{=[STU   Set lens thickness = 3.927  vH`u   Set lens index of refraction = 1.42672 51L:%Af   Set pupil diameter = 4 $o-s?";   DONE!

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