Arizona眼睛模型

E'SDT*EI   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。 ?`O^ ;f   g+<[1;[-   模型 'ShK7j$   * >8EMq\^   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。 3 5L0CM   Table 1. AZ眼睛模型的定义 &CN(PZv   +"k?G   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. >V]9<*c   E\;%,19Ob   光源 Nv6"c<(L=   MHye!T6fO\   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。 u3pFH(   HSAr6h   图1. 光源和提示信息使用 b`=g#B|   WBm)Q#1:   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。 DZ`m{l3H   pv-c>8Wb6   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。 "h7Dye   图2. 字母F光源的设定方法光 4i+%~X@p   d2-oy5cEB   图3. 字母F在视网膜上位置点列图 >s0![coz   qc\D=3#Yp   视网膜的散射 BpYxH#4   WY!4^<|w"   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。 ;YW@ 3F-h   6DgdS5GhT_   图4. 视网膜朗伯散射设定 v_WQ<G?   V{A`?Jl6{   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。 c/v|e&q   *)6\V}`   图5. 视网膜重点采样规格设定 =6Gn? /{   MtN!Xx   脚本 -V[x q   N0vECk   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： !@N?0@$/   图6. 用户对话框的创建与编辑 zR]!g|;f   图7. 用户对话框编辑器 |\G^:V[.   IAq o(Qm   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。 M6Np!0G   余下的脚本计算与屈光度有关的所有参数。 p3{Ff5FZ   8"ZS|^#   分析 \hBzP^*"n   rKyulgP   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 c:>&YGmhu   图7. 字母F在视网膜上颜色分析 p:W]   ;+6><O!G   脚本代码 ctjQBWE   `M 'tuQ M   Option Explicit     'Remove this to enable non-dimensioned variables to be used. ?# _{h   U"+W)rUd   Dim entity As T_ENTITY P*~ vWYH9   Dim op As T_OPERATION \]5I atli   Dim mat As T_MODELMATERIAL $j<KXR   Dim A As Double 7}6CUo   Dim pupilDiam As Double [Z#Sj=z   Dim eID As Long q^Oj/ws   Dim parID As Long OH sA]7S   Dim count As Integer pq&[cA_w   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double q#8yU\J|,   Dim tlens As Double, nlens As Double jnTTj l   Dim curv As Double, conic As Double BI%XF 9{   Dim ok As Long vB{iw}Hi!   ~?HK,`0h>   Sub Main dr:x0>   Sp:w _;{#       '用户输入对话框 18QqZ,t       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 CEc(2q+%i           TextBox 220,21,40,21,.TextBox1 'default: 0 ]S[?tn           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 L+<h5>6           OKButton 40,91,90,21 m6n%?8t           CancelButton 190,91,90,21 [xr^t1           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 )E>yoUhN           TextBox 220,49,40,21,.TextBox2 'default: 4 n-l_PhPQ`       End Dialog vIOGDI>       Dim dlg As UserDialog #fns3=/H   cGgfCF^`       ok = Dialog (dlg) |vl~B|",   4\ Xaou2V[       If ok=0 Then    'cancel button was pressed Mh5> hD           Print "Execution cancelled." :=ek~s.UV           End 9*ZlNZ       End If /[\g8U{5B}   'g,h       'Assign accommodation and pupil diameter & use defaults if field left empty ;<m`mb4x[       If dlg.TextBox1 = "" Then /3~L# jS           A = 0           'Default accommodation |.0~'       Else 5}ftiy[Yc           A = CDbl(dlg.TextBox1) w3);ZQ|       End If 4dPTrBQ?   1*dN. v:5       If dlg.TextBox2 = "" Then kexV~Q           pupilDiam = 4   'Default pupil diameter xwof[BnEZ       Else <%S)6cw(3           pupilDiam = CDbl(dlg.TextBox2) :e;6oC*"q       End If v>B412l   Z,E $4Z       Print " " FrXP"U}Y       Print "Accommodation = " & A & " Diopters" ,mp<<%{u       Print "Pupil Diameter = " & pupilDiam & " mm" iKJqMES   5 k3m"*       ' Calculate new parameters with accommodation gI;"PkN       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness g}D)MlXRq   8$\j| mN       Rant = 12.0 - 0.4*A                     'Radius of anterior lens {Fw"y %a^       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens zH}3J}   hDJG.,r       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens P7XZ|Td4*       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ra T9   W? .469yy       tlens = 3.767 + 0.04*A                  'Lens thickness & 3Zb?   -?)^ hbr       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction :)lG}c   xBTx`+%WS       'Adjust parameters to account for accommodation }]o8}$&(   B=a+cT       '************************************************************************* [StnKQ?"wz       'Aqueous thickness (Position of Lens) oR2?$KF       '************************************************************************* xyk%\&"7       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) W4^zKnH       GetCustomElement eID, entity hFi gY\$m   @9HRGxJ=}       parID = FindFullName( "Geometry.Arizona Eye" ) b},2A'X   9efey? z       ' Delete any shift(s) in z jL\j$'KC       count = 0 Qq`S=:}~x       While GetOperationCount(eID)>count :kR>wX           GetOperation eID, count, op iv~R4;;)           If op.Type="ShiftZ" Then j*?8w(!               DeleteOperation eID,count ^:{8z;w!(               count=count-1 nD BWm`kN           End If //2O#Fg{/           count=count+1 cj>UxU][eS       Wend QX<n^W   A[+)PkR       'Set new shift in Qy"Jt]O       op.Type = "ShiftZ" y2_rm       op.val1 = taq Unb2D4&'       op.parent = parID s`bGW1#io       AddOperation eID, op 8j#S+= l>       Print "Set aqueous humor thickness = " & taq-0.55 6U*CR=4   'cpm 4mT       '************************************************************************* Q`9c/vPU       'Radius and conic constant of anterior lens Xs052c|s       '************************************************************************* K`Kv.4       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) sWr;%<K       GetConic eID, entity, curv, conic x!_5/   'r]6 GC8Z$       SetConic eID, entity, 1/Rant, CCant DH?n~qKpC       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Q&]|W Xv   z;1dMQ,#       '************************************************************************* a*5KUj6/TL       'Radius and conic constant of posterior lens #]jl{K\f#X       '************************************************************************* "Wg,]$IvU       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Fa>f'VXx       GetConic eID, entity, curv, conic 'Eur[~k   ) 1AAL0F\B       SetConic eID, entity, 1/Rpost, CCpost OK80-/8HI       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 'z8FU~oU   NF8<9       '************************************************************************* O.B9w+G=       'Lens thickness (Position of posterior lens surface) )ovAGO       '************************************************************************* \PxT47[@e   JW[6 ^Rw       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Q<V(#)*   v=@y7P1       ' Delete any z-shift(s) \lQ3j8U       count = 0 !ddyJJ^a       While GetOperationCount(eID)>count X3}eq|r9           GetOperation eID, count, op k 3m_L-           If op.Type="ShiftZ" Then zfKO)Itd               DeleteOperation eID,count ts,r,{               count=count-1 GmR3 a           End If We{@0K/O           count=count+1 z='%NZY       Wend U)8yd,qG[%   Mm@G{J\\       'Set new z-shift m:h6J''<Z*       op.Type = "ShiftZ" v>wN O       op.val1 = tlens ,kJ7c;:i       op.parent = parID a|z-EKV       AddOperation eID, op 9s"st\u 4       Print "Set lens thickness = " & tlens T9V=#+8#"   m*]`/:/X[       '************************************************************************* *Mhirz%iD       'Lens index of refraction /8e}c`       '************************************************************************* "M5       eID = FindMaterial( "Lens" ) -E?:W`!       GetModelMaterial eID, mat ,)[9RgsE   ,5$G0       mat.Nd = nlens U}jGr=tu       SetModelMaterial eID, mat 9\.0v{&v       Print "Set lens index of refraction = " & nlens N-upNuv   62HA[cr&)       '************************************************************************* Yc]V+NxxQ       'Pupil diameter V #w$|2       '************************************************************************* |s! _;6       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) *gwaW!=   1.+O2qB       'Adjust pupil diameter (trimming volume inner hole) Cy?]o?_?   ;"nO'wN:h       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" o08g]a   2%WeB/)9       ' Adjust pupil location to just in front of the lens 'l^Bb#)"       parID = FindFullName( "Geometry.Arizona Eye" ) ;=,-C;`       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) :o!Kz`J       count = 0 <5E'`T       While GetOperationCount(eID)>count P6GTgQ<'BA           GetOperation eID, count, op "j_iq"J           If op.Type="ShiftZ" Then 6#U~>r/               DeleteOperation eID,count >;4q               count=count-1 r[!~~yu/o           End If Jt5V{9:('           count=count+1 |V\{U j       Wend DD=X{{;D\"       op.Type = "ShiftZ" tAN!LI+w       op.val1 = taq-0.01 eWDXV-xD       op.parent = parID Zeg'\&w0s       AddOperation eID, op J-<P~9m~I   +zMhA p       Print "Set pupil diameter = " & pupilDiam 3q/Us0jr   o>M^&)Xs       'Update AZ Eye subassembly Description W~mo*EJ'^       eID = FindFullName( "Geometry.Arizona Eye" ) w0g@ <( 3       GetEntity eID, entity @]n8*n       entity.Description = "Accommodation = " & A & "D" m[=SCH-;       SetEntity eID, entity iO*5ClB   :'bZ:J>f       Update aaU4Jl?L       Print "DONE!" KuwhA-IL        IQ<G.   End Sub t,%m-dU   5Yv*f:   如果屈光度是4，光瞳直径是4，则会输出如下数据： G@DNV3Cc   y0p=E^QM   Accommodation = 4 Diopters 1K3XNHF   Pupil Diameter = 4 mm IB# u a:   Set aqueous humor thickness = 2.81 ^4`x:6m   Set anterior lens radius = 10.4 and conic constant = -2.375869 TI3xt-/   Set posterior lens radius = -4.424557 and conic constant = -3.081019 M%_*vD   Set lens thickness = 3.927 /UunWZ u%   Set lens index of refraction = 1.42672 "}_J"%   Set pupil diameter = 4 }'Ap@4   DONE!

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