There are several reasons why the standard X mouse cursors are hard to
track for some people:
when running X on a notebook with low contrast LCD
on normal screens when using high resolution, 1600x1280 e. g.
for visually impaired persons even on normal hardware
In all cases it might help to use enlarged mouse cursors. Ideally this
job should be done by a single X program that automatically enlarges
every mouse cursor.
To my knowledge there is no simple way to write a utility like this,
because the X protocol has no provision to query mouse cursors. For
more details see section
Technical discussion below.
If we aim for a less general goal, though, something can be done:
There is a set of standard mouse cursors that can be found in the
cursor font (try xfd -fn cursor to look at it). Most programs use
these mouse cursors and the key idea is to replace the standard cursor
font with an enlarged version.