Bob Tennent rdt at cs.queensu.ca
Sun Dec 29 21:18:41 CET 2013

It seems the current arrowheads in LaTeX date back to 1992 when
Knuth "improved the arrows, which now are darker and have larger
arrowheads, so that they don't disappear so easily after xeroxing."
Unfortunately, he also said "these fonts are never going to change
again."

So, if, like me, you can't tolerate them (even if \overrightarrow
isn't in use), then you have to use arrows from elsewhere. Here's
the sort of thing I use:

\renewcommand{\rightarrow}{{\,\raisebox{0.58ex}{%
\begin{picture}(6,5)
\put(0,0){\vector(1,0){10}}
\end{picture}
}\,}}

This will work with \overrightarrow, but in some circumstances you
may have to fiddle.

No doubt it can be improved upon and getting arrows from packages
like pstricks and tikz are alternatives.

Bob T.