[dr_kiszonka]

It probably isn't but there are simple exercises to help ameliorate it†. (The problem is that I am frequently too lazy or too busy to do them.)

†unless, in your case, the arrow of causality between vision and computer screen distance is in the opposite direction.

[ChrisLTD]

what exercises should we be doing?

[mtsr]

The obvious one is taking regular breaks from the screen. Focus on things at least 10-30 meters away, so your eyes can relax.

Also, with a good lens setup or with direct projection, VR/AR headsets could theoretically set the focus distance at any distance or even dynamically change it. This would also solve the vergence-accommodation conflict with current headsets.