Shocking Revelation: Eye Tracking Has Problems

With more than a few articles under our belt on the strengths of eye tracking, we thought it might be interesting to point out some of the limitations of eye tracking. We’ve mentioned in previous posts that eye tracking can provide insight into the usability of a website, but without supplementary effort, the data gleaned from eye tracking is just that – data.

Knowing what to do with that data is the key, and there’s not one easy answer for your usability or design problems when it comes to a website. Eye tracking shows where an individual fixates on a page, and while that is indeed valuable, there are several limitations to what in can reveal on its own.

For example, eye tracking can often be misleading as it does not capture our peripheral vision. It typically displays foveal fixations, which reflects the small part of our visual field that makes for the sharpest, finest vision. But in not recording peripheral vision, eye tracking is missing around 98% of our visual field. As we use our peripheral vision to choose where we fixate next, it’s truly a significant loss.

We can see things on a screen without directly fixating on them – for example, as a recent article on the subject states – we can see banner ads on the right side of the page using our peripheral vision. We know enough from their position on the right side of the page, their visual appearance, and from previous web experience, we know they’re ads. We often choose not to fixate on them. This goes for much of a website – we choose not to look at certain parts based on our expectations or previous experience with a site. We don’t want to waste our time and be subjected to ads that get in the way of trying to find information we want, so why look?

Eye tracking visualizations like heat maps do not show peripheral vision, so they can often be misleading. In a heat map, many assume users didn’t see areas without hot spots at all. It’s important to recognize that fixations don’t represent everything a participant sees when looking at a site. They are areas of focus, areas of detail, and that’s it.

In the next post we’ll take a look at a few more negatives in the world of eye tracking. Perhaps these limitations can inspire developers to come up with a fix – something that can record your periphery as well. Stay tuned.

Eyetracking: Is It Worth It?

Related articles:

1. Where’s Waldo?… Eye Tracking Only Registers Half of the Visual Search Process
2. Framework for Eye Tracking Patterns and Usability Problems: Pt 3
3. Framework for Eye Tracking Patterns and Usability Problems: Pt 2
4. Framework for Eye Tracking Patterns and Usability Problems: Part 1
5. Is Eye Tracking for Usability Studies Worth the Trouble?
6. Framework for Eye Tracking Patterns and Usability Problems: Pt 4
7. Fixations and Saccades in Eye Tracking
8. Eye Tracking Studies Suggest Google is Making Us Stupid
9. The Latest in Eye Tracking Web Usability Research pt2
10. Introduction to Eye Tracking: The Anatomy of the Eye