Ask HN: Do eInk readers work?
Do they cause less stress to the eyes?
But a lot depends on the quality of the display you are using. You can reduce a lot of the tiredness caused by lcd displays that are flicker free like this one:
http://www.benq.com/product/monitor/ew2755zh/features/
Also helpful: night-mode, amoled displays because they offer better night mode(as long they are flicker free).