Eye strain. And that can go either way. Blue light for devices or print that's too small in some printed bibles. Generally though paper print is easier on the eyes.But my Kindle is pretty good. With apps you have reference upon reference and commentaries, concordances at your finger tips for deeper meaning and deep studies without flipping a bunch of pages or getting extra books.. And several are free or low cost. Course your device conks out you got nothing so you still need a paper and ink bible or two around.