The legibility of numerals
By varying the skeleton of the digits we identified versions of the digits ‘1’, ‘3’, ‘7’ and ‘9’ that are more legible than other versions.

To enhance the peripheral legibility of numerals we designed three versions of the digits from 1 through 9 by modifying their skeletons while controlling for variations of other physical parameters. Observers identified the different versions of the digits in random three-digit strings, presented within their peripheral visual field.

Our results showed that the digit ‘1’ should have a narrow design without a crossbar at the bottom, the digits ‘3’ and ‘9’ benefit from open apertures, and the digit ‘7’ should have a straight leg and no serif at the horizontal bar.

For more see:
Beier, S., Bernard, J.B. & Castet, E. (2018) ‘Numeral legibility and visual complexity’, Proceedings of DRS2018, Design Research Society, vol. 5, 1841-1854, Limerick, 25th-28th June.