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, 1600×1280 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.