%!
48 dup scale
1 48 div setlinewidth
4 4 translate
(lenses.inc) run

gsave
newpath
0.05 setlinewidth
-3 1.25 moveto
2 1.25 lineto 
-3 -1.25 moveto
2 -1.25 lineto 
stroke 
grestore

gsave
newpath
0.01 setlinewidth
0 1.15 moveto
4 1.15 lineto 
0 -1.15 moveto
4 -1.15 lineto 
stroke 
grestore

gsave
newpath
/x .90 def
/y 1 def
8 {
0 y moveto
0 x lineto
stroke
/y y .3 sub def
/x x .3 sub def 
} repeat
grestore




gsave
newpath
1 0 1 270 90 arc
closepath
stroke
newpath
4 0 1 90 270 arc
closepath
stroke
grestore



gsave 
newpath
/x -0.4 def
/s -3 def

/Po [-3 x] def
/Vo [s cos s sin] def
/P1 Po Vo [1 0 0] line-intersection def
Po 0 get Po 1 get moveto
P1 0 get P1 1 get lineto
stroke

/po P1 def
/vo [2 0] def
/p1 po vo [1 0 -1] line-intersection def
po 0 get po 1 get moveto
p1 0 get p1 1 get lineto

/n1 [1 0] P1 gradient normalized def
/v1 n1 vo 1.4 refraction def
/p2 p1 v1 [1 0] 1 hit def
p2 0 get p2 1 get lineto

/n2 [1 0] P1 gradient normalized def
/v2 n2 v1 1 refraction def
/p3 p2 v2 [4 0] 1 hit def
p3 0 get p3 1 get lineto

/n3 [4 0] P1 gradient normalized def
/v3 n3 v2 1.5 refraction def
/p4 p3 v3 [1 0 -4] line-intersection def
p4 0 get p4 1 get lineto

/n4 [4 0] P1 gradient normalized def
/v4 n4 v3 .6 refraction def
/p5 p4 v4 [1 0 -6] line-intersection def
p5 0 get p5 1 get lineto
stroke
grestore 


gsave
newpath
/x 0.4 def
/s 3 def

/Po [-3 x] def
/Vo [s cos s sin] def
/P1 Po Vo [1 0 0] line-intersection def
Po 0 get Po 1 get moveto
P1 0 get P1 1 get lineto
stroke


/po P1 def
/vo [2 0] def
/p1 po vo [1 0 -1] line-intersection def
po 0 get po 1 get moveto
p1 0 get p1 1 get lineto

/n1 [1 0] P1 gradient normalized def
/v1 n1 vo 1.4 refraction def
/p2 p1 v1 [1 0] 1 hit def
p2 0 get p2 1 get lineto

/n2 [1 0] P1 gradient normalized def
/v2 n2 v1 1 refraction def
/p3 p2 v2 [4 0] 1 hit def
p3 0 get p3 1 get lineto

/n3 [4 0] P1 gradient normalized def
/v3 n3 v2 1.5 refraction def
/p4 p3 v3 [1 0 -4] line-intersection def
p4 0 get p4 1 get lineto

/n4 [4 0] P1 gradient normalized def
/v4 n4 v3 .6 refraction def
/p5 p4 v4 [1 0 -6] line-intersection def
p5 0 get p5 1 get lineto
stroke
grestore 

gsave
/Helvetica-Bold findfont
.3 scalefont
setfont
1 -1.5 moveto
( ocular system) show
grestore


gsave
/Helvetica-Bold findfont
.2 scalefont
setfont
-3 1 moveto
(rays produced by obective) show
grestore


gsave
/Helvetica-Bold findfont
.25 scalefont
setfont
-3 1.75 moveto
( image produced ) show
grestore


gsave
/Helvetica-Bold findfont
.25 scalefont
setfont
-3 1.5 moveto
( 
by objective) show
grestore