Which font is clear in small size?
So something like Sitka Small will be very readable at small text sizes. Or Verdana, which while designed for low resolution screens, works very well for readability at tiny sizes. You can also look at fonts like Bell Centennial which was designed for phone books (bad printing, bad paper, tiny size, legible).
What’s the most readable font?
Design Decoded: The Top 12 Easy to Read FontsHelvetica. Along with Georgia, Helvetica is considered to be one of the most easily read fonts according to The Next Web. PT Sans & PT Serif. Can’t decide whether serif or sans-serif is for you? Open Sans. Quicksand. Verdana. Rooney. Karla. Roboto.
Which font is best for eyes?
Sans-serif fonts like Arial and Verdana, which have more spacebetween letters, can make words appear crisper and easier to read from farther away, taxing your vision less. Windows font rendering called ClearType is better for your eyes than OSX font rendering. However on OSX fonts are more smooth and beautiful.