Take
regular breaks from the screen, this has 2 advantages:
It
gives your focussing system a rest.
It
reminds your brain that there are 'other' distances to focus at.
This can help prevent your focussing system from 'fixing' at the
mid-distance avoiding a consequent drop in far distance.
Blink
to refresh your tears. Tear comfort (supplement) drops are available
to ease any discomfort.
Have an eye examination (and include the visual stress assessment) to make sure….
your eyes are working efficiently. You may be able to see very clearly, and yet your visual system
may be struggling. With VDU work it's not what you see but how
you see.