Arizona眼睛模型

DQ8/]Z{H   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。 h3 HUdu   Qhj']>#g   模型 w> B}w   X HA|v^   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。 qiet<F   Table 1. AZ眼睛模型的定义 'u.Dt*.Uq   OP\jO DX   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. :|(YlNUv   Nk@-yZ@,8   光源 |pHlBzHj   K^!#;,0   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。 A l;a~45   N5K(yY_T   图1. 光源和提示信息使用 N'y<<tTA   FF#Aq   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。 L,R}l0kc   ?jR#txR   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。 (K[e=0Rf   图2. 字母F光源的设定方法光 ~g!!#ad   s={>{,E   图3. 字母F在视网膜上位置点列图 6 5zx<   62ru%<x=   视网膜的散射 4 Y=0>FlY0   i1x4$}   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ,<Cl^ ^a,   >\K=)/W2   图4. 视网膜朗伯散射设定 Y-})/zFc   4AL,=C3   注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 z9 0JZA   J3y _JoS   图5. 视网膜重点采样规格设定 jvQ^Vh!mC   _Yo)m|RaB   脚本 +7%?p"gEY\   bYLYJ`hH<R   内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： \SmsS^z(]   图6. 用户对话框的创建与编辑 HKb V@NW   图7. 用户对话框编辑器 CE M4E   A o*IshVh   如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 (^W}uDPCB   余下的脚本计算与屈光度有关的所有参数。 S$SCW<LuN   AO`@&e]o   分析 hbYstK;]Z   zx<t{e7   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 8G)~#;x1   图7. 字母F在视网膜上颜色分析 >e;jGk?-   (_#E17U)_   脚本代码 346 z`5   97 SS0J   Option Explicit     'Remove this to enable non-dimensioned variables to be used. T[OI/ WuK   wDi/oH/H   Dim entity As T_ENTITY 5 v.&|[\k   Dim op As T_OPERATION P8=|#yCi   Dim mat As T_MODELMATERIAL PW@ :fM:q   Dim A As Double l'm|**   Dim pupilDiam As Double ,W+=N"`a'   Dim eID As Long e,#w*|   Dim parID As Long sR$abN+u   Dim count As Integer gm5%X'XL   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double q/:]+   Dim tlens As Double, nlens As Double VEa"^{,w   Dim curv As Double, conic As Double &(<>} r   Dim ok As Long ]4B;M Ym*   t$qIJt$   Sub Main Mm,\e6#*   kj|Oj+&       '用户输入对话框 i5(qJ/u       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 CSjd&G*ZB           TextBox 220,21,40,21,.TextBox1 'default: 0 3KqRw (BK           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 An>ai N ]           OKButton 40,91,90,21 t0c S.hi           CancelButton 190,91,90,21 i'CK/l.H           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 r=.@APZB           TextBox 220,49,40,21,.TextBox2 'default: 4 kt`ln       End Dialog _fgsHx>l7       Dim dlg As UserDialog FLJ&ZU=s   :BR_ %$       ok = Dialog (dlg) OE[7fDe'   A%EhRAy       If ok=0 Then    'cancel button was pressed \$Ky AWrZi           Print "Execution cancelled." 0-OKbw5%=b           End [,st: Y       End If O_s/BoB@   JkR%o #>5       'Assign accommodation and pupil diameter & use defaults if field left empty VO1       If dlg.TextBox1 = "" Then @Wd(>*"zw           A = 0           'Default accommodation {pi_yr3       Else 7gLk~*           A = CDbl(dlg.TextBox1) w)K547!00       End If XU<owk   ":e6s c o       If dlg.TextBox2 = "" Then )M.g<[=^           pupilDiam = 4   'Default pupil diameter ,c&t#mu*0       Else U*N{H$ACuR           pupilDiam = CDbl(dlg.TextBox2) l %zbx"%x       End If <%^WZ:c   V!*1F1       Print " " |H8C4^1Rq       Print "Accommodation = " & A & " Diopters" b!MN QGs       Print "Pupil Diameter = " & pupilDiam & " mm" d8 ~%(I9   GLub5GrxR       ' Calculate new parameters with accommodation =MJRQV67       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness AzzHpfv,   VJA/d2Oys       Rant = 12.0 - 0.4*A                     'Radius of anterior lens F@z%y'5 Z*       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens *Q2 oc:6   f3vl=EA4|       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens b&,ZmDJh       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens a{^2c!   &RuTq6)r       tlens = 3.767 + 0.04*A                  'Lens thickness TqS s*as5   08AD~^^       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction lZkJ<*z#   (!m6>m2       'Adjust parameters to account for accommodation c# u_%*   =>o !       '************************************************************************* 3GL?&(eU;       'Aqueous thickness (Position of Lens) "IpbR       '************************************************************************* p4\s KF8-       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) s 7%iuP       GetCustomElement eID, entity REcKfJTj   1W.oRD&8j/       parID = FindFullName( "Geometry.Arizona Eye" ) ~T9QpL1OJ   9I5AYa?       ' Delete any shift(s) in z >^W6'Q$P<       count = 0 TWRnty-C       While GetOperationCount(eID)>count &&jQ4@m}j           GetOperation eID, count, op 9%R"(X)           If op.Type="ShiftZ" Then fwx^?/5j               DeleteOperation eID,count `X()"Qw               count=count-1 j,%i.[8S           End If 2!9W:I7           count=count+1 eC 2~&:$L       Wend Gys-Im6>~@   7[L%j;)bw       'Set new shift in m'G=WO*%       op.Type = "ShiftZ" f `b6E J       op.val1 = taq fMHw=wJQ       op.parent = parID EHl~y=9       AddOperation eID, op WcXNc`x       Print "Set aqueous humor thickness = " & taq-0.55 5KTFf6Uq   %y_pF?2@q       '************************************************************************* xU{0rM"       'Radius and conic constant of anterior lens +|<bb8 %       '************************************************************************* D;48VK/Q       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) >#;_Ebl@       GetConic eID, entity, curv, conic L*p7|rq$"   G^;]]Ji"       SetConic eID, entity, 1/Rant, CCant &{#6Z       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Jp8,s%   cN2Pl%7       '************************************************************************* F}F{/       'Radius and conic constant of posterior lens  :vS/Lzk       '************************************************************************* ]A+t@/k       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ]$.w I~J%       GetConic eID, entity, curv, conic |Ul4n@+2   ::GW       SetConic eID, entity, 1/Rpost, CCpost [%/B"wTt       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost vUL@i'0&o   ht+wi5b       '************************************************************************* (KvN#d 1\       'Lens thickness (Position of posterior lens surface) 6/'X$ }X       '************************************************************************* %3=T7j   A??a:8id^       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) y+7+({ w<   ]|IeE!6       ' Delete any z-shift(s) fI.X5c>WK       count = 0 /L]@k`.q@       While GetOperationCount(eID)>count P $r!u%W           GetOperation eID, count, op g <w1d{Td           If op.Type="ShiftZ" Then <h~uGBS"               DeleteOperation eID,count I;<__               count=count-1 iHdX           End If wXYT(R           count=count+1 R (}!gv}s       Wend =8]Ru(#Ig   DU5rB\!.~       'Set new z-shift ;?-{Uk       op.Type = "ShiftZ" plzwk>b_       op.val1 = tlens G!D~*B9G       op.parent = parID UpiZd/K       AddOperation eID, op A~s6~       Print "Set lens thickness = " & tlens @t e}Asv   ,&@FToR       '************************************************************************* QdD@[       'Lens index of refraction a6d|Ps.\!       '************************************************************************* daf-B-       eID = FindMaterial( "Lens" ) `"xzC $       GetModelMaterial eID, mat '&]6(+I>   zR=g<e1xe       mat.Nd = nlens IpKI6[2{`f       SetModelMaterial eID, mat %yR80mn8       Print "Set lens index of refraction = " & nlens # ?u bvSdU   kc@\AZb       '************************************************************************* *JWPt(bnI       'Pupil diameter %2?"x*A       '************************************************************************* lZ,$lZg9Z       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) SS;'g4h\6   *@YQr]~ ;       'Adjust pupil diameter (trimming volume inner hole) n*~#]%4   k6;pi=sYNW       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Kc3/*eu;   |g\CS4$       ' Adjust pupil location to just in front of the lens 3 "|A5>Vo       parID = FindFullName( "Geometry.Arizona Eye" ) @d^MaXp_P       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ?J"Y4,{       count = 0 ^<aj~0v       While GetOperationCount(eID)>count OJ7 y           GetOperation eID, count, op grDz7\i:           If op.Type="ShiftZ" Then #vR5a}BAk               DeleteOperation eID,count a7]Z_Gk               count=count-1 +J !1z           End If NL"w#kTc()           count=count+1 Yp$@i20       Wend 'f. 5hX(Y       op.Type = "ShiftZ"  n+'s9       op.val1 = taq-0.01 Ap}`Q(.       op.parent = parID ;|CG9|p       AddOperation eID, op r"lh\C|   "W"r0"4       Print "Set pupil diameter = " & pupilDiam kChCo0Q> 1   ,^T0!k$       'Update AZ Eye subassembly Description L%.=SbmS       eID = FindFullName( "Geometry.Arizona Eye" ) 1a#R7chl       GetEntity eID, entity c+<gc:#jy       entity.Description = "Accommodation = " & A & "D" wY7+E/       SetEntity eID, entity {6wy}<ynC+   ZD8E+]+       Update V##TG0       Print "DONE!" ,\PTn7_        #@L<<Q8}   End Sub ^cojETOv   u%CJjy   如果屈光度是4，光瞳直径是4，则会输出如下数据： Uetna!ABB   z|N*Gs>,   Accommodation = 4 Diopters .@Jos^rxgJ   Pupil Diameter = 4 mm 3>^S6h}o   Set aqueous humor thickness = 2.81 0h"uJco,   Set anterior lens radius = 10.4 and conic constant = -2.375869 ,Q8h#0z r   Set posterior lens radius = -4.424557 and conic constant = -3.081019 I#CS;Yh95   Set lens thickness = 3.927 Lor__ K   Set lens index of refraction = 1.42672 /oU$TaB>(   Set pupil diameter = 4 tkhEjTZ   DONE!

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