Hello all and welcome to this presentation about digital eye strain in gaze-based interactive
systems. My name is Teresa and this is work that we conducted with colleagues from Ulm
University and University of Stuttgart.
Digital eye strain is a well-known, frequently-occuring negative byproduct of using digital screen-based
devices.
Researchers have started to investigate it already when digital devices first entered
the workplace 60 years ago.
Nowadays 60%-90% of computer users are already affected and with the constant increase of
digital devices in our lives, one can assumte that the problem will become a serious health
problem in our digital society. Mark Rosenfield even suggests that its assessmennt shoud become
an integral part of todays standard eye examination because so many people are affected.
By experiencing symptoms like eyestrain, tired or dry eyes the problem negatively impacts
users' general well-being and quality of life. Gaze-based interfaces further increase these
problems as they add an active channel to the eye's primary function as a perceptual
organ. As such, they often require unnatural gaze behavior like gaze commands that put
further strain on the eyes.
However, prior research on gaze-based interfaces has largely neglected these risks. To gain
an overview of the prevalence of DES in eye-based interaction we conducted a systematic review.
In particular, we aimed to answer the question of how the gaze interaction community has
experienced DES as a problem in their research what types of causes exist, what types of
assessment methods they use, and what solution approaches exist to counter the problem.
We started with the definition of two sets of keywords, one including DES-related terms,
and one including gaze-interaction related terms. As gaze interaction is closely coupled
to digital device use in general, and causes that stem from the one or the other are difficult
to distinguish, we included a broader set of keywords in the interaction-related set
to also detect general problems with DES in interactive systems. In the paper we report
the results of our analysis following the PRISMA process for reporting systematic reviews.
We used a deductive approach of content synthesis, as we were looking for predefined concepts
in the data. Specifically, we were looking for the concepts assessment method, causes,
solutions, or qualitative feedback on DES that is not specifically related to one of
the other terms. The final set consists of 92 papers with 47 papers that were related
to eye tracking applications and 45 papers that addressed causes, influence, and solutions
of general interaction techniques and devices on DES.
In this talk, I will focus on the causes and solutions, dominantly on the ones regarding
gaze-based interfaces. So, starting with the set of causes: We found passive causes that
are device-based factors and include close viewing distance, display or user interfaces
properties, and the vergence-accommodation conflict that occurs with stereoscopic displays.
On the other hand, active causes are the ones that actually stem from using the eyes to
perform an input event. For example, we found that multiple gaze commands or frequently
switching between gaze interaction techniques can cause eye strain. The two main active
causes that we extracted from the reviewed papers are prolonged fixation duration and
a large number of long saccades. Most of the gaze-interaction techniques that we reviewed
include both in some form. Some more detailed results that we found are that DES occurs
with and without visual feedback, and independently of whether gaze was used directly or indirectly.
Furthermore, long fixation times seem to have a stronger impact on eye strain than the number
of saccades. So, it seems that digital eye strain is a prevalent problem in eye-based
interaction that occurs in a variety of application cases.
In terms of solutions, we found a general set that includes general posture correction
or correcting close viewing distances. Another cluster of solutios was found for the dry
eye syndrome, where we found several works that aimed to increase blink rate. For active
causes, we found only a few papers that considered digital eye strain in the design of explicit
gaze-based techniques. For example by including natural viewing behavior or deliberately choosing
to induce short instead of long saccades.
In the following, i will summarize our results in several key challenges and give recommendations
for future research.
The first challenge that we derive is that the large variety of measures makes it difficult
to compare results among studies. While some apply very detailed questionnaires, others
report single-item feedback. Also, the number of different terms make it difficult to find
all relevant works to this topic. Regarding the solutions, our survey revealed a lack
of solutions to active causes. Only 5 of 47 papers that focused on explicit gaze-based
interaction mentioned to actively consider DES in the design of their techniques.
Lastly, we encountered a discrepancy between awareness and actions. We found a lot of papers
that measured eye strain, although more as a side-note, and did not report on the results.
Others reported medium to high values but did not dicuss implications thereof. On the
other hand, many researchers seem to be aware to the problem as they include breaks in their
study design or don't let participants perform an interaction technique for a prolonged time
period. So, DES is known in the community but not yet fully acknowledged, because technique
are often investigated in short term settings, and long-term effects are unknown.
Our recommendations are that digital eye strain should become an additional measure to be
included in the evaluation of new gaze-based interaction techniques. Second, longitudinal
studies of gaze interaction methods are important and should be conducted to reveal potential
straining influences of these techniques. Both require the development of a consistent
methodology to measure digital eye strain that would lead to standardized, comparable
measures. For potential solutions, we found that an implicit integration would be desirable,
as users are aware to DES and even care about it, but often don't want to take proactive
actions. Therefore, we as designers of gaze interaction techniques are in demand of including
healthy usage already in the design. To conclude our key take aways are that gaze interaction
technqiues cause digital eye strain but often these negative impacts are not further discussed.
Furthermore, there is no clear methodology how DES should be assessed and evaluated and
current solutions mostly focus on passive, but not active causes. So, this work basically
is a call to change evaluation practices and start investigating alleviation techniques
of digital eye strain in gaze-based interactive systems.
Thank you for your attention, and I'm looking forward to the discussion.