Your eyes need to focus and converge on the display surface irrespective of the distance or orientation of the display and irrespective of the font size.
But as a general rule, the further the display surface the less your eye muscles need to work. So if you can put your display 3m away from your eyes that is better than putting it 30cm away.
On my desk, about 90cm from my face is the furthest I can manage, but if you have more space in your work room, by all means put the display significantly further than that.
But as a general rule, the further the display surface the less your eye muscles need to work. So if you can put your display 3m away from your eyes that is better than putting it 30cm away.
On my desk, about 90cm from my face is the furthest I can manage, but if you have more space in your work room, by all means put the display significantly further than that.