optician chart font

[siwanh]

not really probably in right subject, but does anyone out there know what's the font Opticians use on thier charts?!

[dundurn]

http://www.i-see.org/eyecharts.html

There's a section on wikipedia also - Courier Bold approximates the font used but the "real" version seems to be called Snellen after the Dutchman who invented the idea.