@brandon @Zorque This has been researched about hundred times and for most readers in the Roman alphabet lines between 55 and 70 characters - a space is a character too - are easiest to read. Hence scientific articles in Latex and similar later text mark up languages use two columns on a A4 paper.

I can say i have experienced that occasionally, but it had less to do with being hard to read visually and more to do with just not caring about what I'm reading. Which seems less of a "We need to make this easier to read" and more a "We need to trick people into thinking they're reading something meaningful" problem.

Is it something to do with shortsightedness? Maybe an ADHD thing that somehow doesn't affect me for some reason? Maybe just I'm super good at basic visual spatial orientation?

Or is it just that people read with such small text that it's hard to differentiate between lines? I honestly can't fathom an inability to read a line in any other circumstances.