Here's an animation/toggle I did comparing Roboto & Helvetica: http://und.st/pqCj4I.
In the lowercase, there are only 5 letters (a, e, f, g, k) that a normal person would have much chance of distinguishing, even some of those are subtle. The other 21 letters appear virtually identical.
In the lowercase, there are only 5 letters (a, e, f, g, k) that a normal person would have much chance of distinguishing, even some of those are subtle. The other 21 letters appear virtually identical.