The International Conference on Human Factors in Computing & Informatics (southCHI 2013) was an opportunity to present the latest results of the IFeL Usability Lab in the domain of eReading research. In a pilot experiment for our recent eReading study we tested on-screen reading (LED and eInk) under different contrast conditions.
Focusing on the type of contrast (i.e. light text on dark background vs. dark text on light background) and its influence on readability are discussed controversialy in internet forums and blogs related to e-reading and web design.
Most seems to think that a negative contrast (i.e. dark text on light background) is suited best for reading, while others claim positive contrast (i.e. light text, dark background) to be more relaxing for the eyes and less fatiguing.
Since previous research is inconclusive on this matter, we conducted an eye tracking study comparing central eye movements involved in reading.
The results showed two things:
- First, there was no significant difference in central eye movements involved when reading on-screen-text either dark-on-light or light-on-dark.
- Second, the subjective readability-ratings showed a significant preference of dark-on-light text materials.
What does this imply for web and e-reading designers? Though we have yet to analyze the follow-up study’s data, it actually seems to make no difference to apply either positive or negative contrast, as long as it is distinctive.
But – the human factor – people seem to prefer reading with negative contrast.