Mouse pointer

[Wolfgang Engelmann]

This is not directly lyx related.
If I use the mouse in a lyx document the "I" like pointer is too small 
for me to see it immediately. This is true also for Mozilla Thunderbird: 
It is too small in the mail text, although it is ok (and shown as a 
thick enough arrow) outside the text.
Coming back to the lyx document: Once I have clicked with the mouse a 
position, it is marked well (red and thick -forgot where I have set it 
in Lyx), but as soon as I am back in the text it is too thin.
Does somebody know where I can change this to a better recognizable sign 
(perhaps coloured).
I am using Debian 10.6 and I am getting older (eyes).
Wolfgang