Arizona眼睛模型

GUJaeFe   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。 %E95R8SL   smpz/1U   模型 *RQkL'tRf   k\T,CZ<   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。 $td=h)S^`   Table 1. AZ眼睛模型的定义 V[R33NYG   u.wm;eK[   在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 5} 9}4e   @_tQ:U,v   光源 #Y3:~dmJ-   'E2\e!U/   多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 Y"GU"n~   m@hmu}qz-   图1. 光源和提示信息使用 EK^B=)q6:W   lF]cUp#<   除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 uaMf3HeYV   WxE4r   在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 VZ?"yUZ Id   图2. 字母F光源的设定方法光 gO*:<B g   r7z8ICX'q   图3. 字母F在视网膜上位置点列图 &u62@ug#}   x.rOP_rs   视网膜的散射 C3n_'O   SbNs#   在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 V6.xp{[   PiD%PBmUl   图4. 视网膜朗伯散射设定 'iM;e K   |s&jWM$   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。 3PB#m.N<   3/P#2&jt   图5. 视网膜重点采样规格设定 lW^bn(_gQ   j)K[A%(   脚本 BlF]-dF\   <MgR x9   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： `6KTQk'   图6. 用户对话框的创建与编辑 4\) "Ih   图7. 用户对话框编辑器 0f.rjd   E|ce[|2   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。 $sDvE~f0n   余下的脚本计算与屈光度有关的所有参数。 ?@U7tNI   yoKl.U"&   分析 XeD9RMT   $d1+d;Mn   屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 .\kcWeC\   图7. 字母F在视网膜上颜色分析 Cx$M   +{V"a<D$m   脚本代码 @SREyqC4   %vjLw`   Option Explicit     'Remove this to enable non-dimensioned variables to be used. *={` %   G1 ?."   Dim entity As T_ENTITY t.sbfLu   Dim op As T_OPERATION i{8T 8   Dim mat As T_MODELMATERIAL s;'XX}Y   Dim A As Double #%CbZw@hJ9   Dim pupilDiam As Double }`g:)gJ   Dim eID As Long ueO&%   Dim parID As Long \Q+9sV 5,[   Dim count As Integer W2L:   Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double G% w VQ|1   Dim tlens As Double, nlens As Double j4wcxZYY~   Dim curv As Double, conic As Double Z:3N*YkL   Dim ok As Long nQuiRTU<   a []Iz8*6e   Sub Main cE}R7,y   E#t;G:+A       '用户输入对话框 YfBb=rN2s       Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 # Ny           TextBox 220,21,40,21,.TextBox1 'default: 0 3$Ew55           Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 }q1@[ aE           OKButton 40,91,90,21 TJ@@kSSbl           CancelButton 190,91,90,21 8X=cGYC#           Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ,}15Cse           TextBox 220,49,40,21,.TextBox2 'default: 4 KlMrM% ;y       End Dialog +g_+JLQ       Dim dlg As UserDialog BZy&;P    %Gp%l       ok = Dialog (dlg) 1iq,Gd-G.   v.,|#}0 o       If ok=0 Then    'cancel button was pressed +TW9BU'a^           Print "Execution cancelled." c$),/0td|           End J+f .r|?       End If ;seD{y7!   |;2Y|>=       'Assign accommodation and pupil diameter & use defaults if field left empty >jEn>H?       If dlg.TextBox1 = "" Then :fI|>I ~           A = 0           'Default accommodation )3<|<jwcx       Else h8;B+#f`           A = CDbl(dlg.TextBox1) /C(lQs*l       End If D"o}XTH   :TU;%@7       If dlg.TextBox2 = "" Then ,]?Xf>           pupilDiam = 4   'Default pupil diameter )(~s-x^\z@       Else 1@Dp<Q           pupilDiam = CDbl(dlg.TextBox2) y6.}h9~       End If lqFDX d   ~m^.&mv3/       Print " " Qs2E>C       Print "Accommodation = " & A & " Diopters" SH>L3@Za       Print "Pupil Diameter = " & pupilDiam & " mm" L3:dANG   7'wt/9       ' Calculate new parameters with accommodation DQ7+       taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness m&/{iCwp   %bo0-lnp       Rant = 12.0 - 0.4*A                     'Radius of anterior lens dz fR ^Gv       CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens V@gweci   ,"?h_NbF       Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ,KvF:xqA       CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens % 1Y!|306   aty"6~       tlens = 3.767 + 0.04*A                  'Lens thickness ylm*a74-X   Y<('G5A       nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 3nb&Z_/e   n_;qB7,,       'Adjust parameters to account for accommodation W7I.S5   _@I8B       '************************************************************************* >ZMB}pt`       'Aqueous thickness (Position of Lens) v"M5';ZS>       '************************************************************************* 61|uvTX       eID = FindFullName( "Geometry.Arizona Eye.Lens" ) &u5OL?>       GetCustomElement eID, entity ^Rr0)4ns   yZup4#>8       parID = FindFullName( "Geometry.Arizona Eye" ) }*.S=M]y$   ~jdvxoX-       ' Delete any shift(s) in z _'9 ("m V       count = 0 ~`'!nzP5H       While GetOperationCount(eID)>count 6&~8TH           GetOperation eID, count, op W}&[p=PAS           If op.Type="ShiftZ" Then b-pZrnZ!               DeleteOperation eID,count V1Yab#               count=count-1 eQh@.U*S)           End If *^j'G^n           count=count+1 hdky:2^3       Wend [RtTi<F^   6&8([J       'Set new shift in l ;"v&?       op.Type = "ShiftZ" VO#x+u]/       op.val1 = taq g)7~vm2/,       op.parent = parID qYD$_a       AddOperation eID, op  lJaR,,       Print "Set aqueous humor thickness = " & taq-0.55 zTtn`j$   m80e^       '************************************************************************* on?<3eED       'Radius and conic constant of anterior lens 5,/rh,?       '************************************************************************* A-5xgp,       eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Ore>j+       GetConic eID, entity, curv, conic yW::`   cj ?aCVa       SetConic eID, entity, 1/Rant, CCant gDHgXDD_b       Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant bI~ R6o   uw'>tb@       '*************************************************************************  5`su^       'Radius and conic constant of posterior lens Z(Styn/x       '************************************************************************* 0$RZ~       eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) l=EnK"aU       GetConic eID, entity, curv, conic SU,S1C_q8   JbT+w\o       SetConic eID, entity, 1/Rpost, CCpost >R9Q|       Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 0,~f"Dyqy   a7?z{ssEi       '************************************************************************* XO[S(q       'Lens thickness (Position of posterior lens surface) F@m]Imn5Dx       '************************************************************************* <sU?q<MC   c6v@6jzx0Y       parID = FindFullName( "Geometry.Arizona Eye.Lens" ) yVF1*#"   W 7xh       ' Delete any z-shift(s) R _#x       count = 0 JQ5E;8J>       While GetOperationCount(eID)>count ?'RB)M=Og7           GetOperation eID, count, op A0mj!P9           If op.Type="ShiftZ" Then @9,=|kxK               DeleteOperation eID,count m+66x {M2c               count=count-1 UZcsMMKH           End If T@K= *p           count=count+1 ?= G+L0t       Wend -cDS+*[   z1dSZ0NoA       'Set new z-shift 36]pE<       op.Type = "ShiftZ" "LwLTPC2       op.val1 = tlens }s+ t*z       op.parent = parID U}#3LFr.?       AddOperation eID, op gMXs&`7P       Print "Set lens thickness = " & tlens /-J   2@TgeV0Y[       '************************************************************************* o!6~tO=%       'Lens index of refraction 5OHg% ^       '************************************************************************* }j+Af["W?       eID = FindMaterial( "Lens" ) r4YiXss       GetModelMaterial eID, mat " V[=U13   ?L K n       mat.Nd = nlens ^pB}eh.@U       SetModelMaterial eID, mat Ux[2 +Cf       Print "Set lens index of refraction = " & nlens `efC4#*!!   s<z`<^hRe       '************************************************************************* ON(OYXj       'Pupil diameter t`M4@1S"'       '************************************************************************* GG0H3MSc       eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) bEQy5AX   <bSG|VqnH       'Adjust pupil diameter (trimming volume inner hole) `i!BXOOV{   \eF_Xk[       SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" #}PQ !gZ   ?xa70Pb{;       ' Adjust pupil location to just in front of the lens }l>\D ~:M       parID = FindFullName( "Geometry.Arizona Eye" ) }Z/[ "       eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) N_ :H kI6       count = 0 .2Q4 EbM2       While GetOperationCount(eID)>count t]3> X           GetOperation eID, count, op v9,<2           If op.Type="ShiftZ" Then YYE{zU               DeleteOperation eID,count Fe[)-_%G               count=count-1 vU,V[1^a           End If =l)D$l           count=count+1 'c&[kMR       Wend tG7F!um(       op.Type = "ShiftZ" DX2_}|$!       op.val1 = taq-0.01 >^=;b5I2K       op.parent = parID K N Y       AddOperation eID, op 'iM#iA8   %nS(>X<B       Print "Set pupil diameter = " & pupilDiam Z bW!c1s{   [S~/lm       'Update AZ Eye subassembly Description +Rj8"p$K       eID = FindFullName( "Geometry.Arizona Eye" ) UF&B7r       GetEntity eID, entity &%UZ"CcA       entity.Description = "Accommodation = " & A & "D" q"48U.}T       SetEntity eID, entity ]x1;uE?1J   AqA. ,;G       Update /Hs\`Kg"!       Print "DONE!" P5JE = &M        }ed{8"bj   End Sub |C"zK   _v#Vf*#   如果屈光度是4，光瞳直径是4，则会输出如下数据： 9bQD"%ha=d   bA-/"'Vp9   Accommodation = 4 Diopters s/l>P~3=   Pupil Diameter = 4 mm  ;b5^)S   Set aqueous humor thickness = 2.81 DL*&e|:q   Set anterior lens radius = 10.4 and conic constant = -2.375869 ]Sey|/@D   Set posterior lens radius = -4.424557 and conic constant = -3.081019 y$}o{VE{x   Set lens thickness = 3.927 w t6&N{@   Set lens index of refraction = 1.42672 LE|DMz|J   Set pupil diameter = 4 _,<@II   DONE!

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