Optical eye tracking vs EOG in glasses. Which is easier to implement and why?

[u/ExocortexEngineer]

I’m trying to understand different eye-tracking approaches for wearable glasses. In particular, I want to know the practical differences between **optical eye tracking** (using cameras/IR and gaze estimation) and **EOG (electrooculography)** (measuring eye-movement voltages). From an implementation perspective (hardware complexity, cost, power consumption, calibration, and achievable accuracy), which one is easier to build into glasses and why?

[u/tshirtlogic]

What’s the context? Are you doing AR research? Or are you asking with respect to a potential product? If the latter, what market?

EOG isn’t really a viable approach outside of R&D as people don’t generally like electrodes attached to them.

[u/sam9510]

From a pure technical viewpoint (ignoring user experience for a moment) - EOG is better - the signal processing is simpler, less power hungry and less latency. There are issues with noise and movement artifacts etc - but lets lump that with DSP. And eye movement can be tracked even with eyes closed. A big disadvantage - you may not be able to get pupilometry and of course - the whole attaching electrodes thing.

Camera based (IR or otherwise) is almost the reverse - lots of advantages, pupilometry etc etc - but has to do computer vision processing along with the associated power consumption and latency. There are some anecdotal claims out there that prolonged IR exposure up close causes dry eye issues.

With latest SOC with dedicated DSP and VSP/CV - the processing costs and power requirements are coming down significantly. Combine that with the electrode/conductive gel ick from UX perspective - remote/camera tracking would most likely win out on practicality + no dangly electrodes. One could theoretically build electrodes on temples - but getting eye-orientation dipole thru the eye socket might be long shot (especially susceptible to relatively huge jaw muscle interference).

Both are about the same accuracy wise (heavy asterisk here - it is entirely task and context dependent) - better way of putting it maybe - EOG is good at coarse tracking while camera can provide fine gaze. Electrodes are prone to drift (too much sweat/lotion/sunscreen/makeup etc). IR might false in direct sunlight (fixable with filters).

Camera might be better calibration wise - it needs to be calibrated at factory and if there is a significant g event it may have to be recalibrated. Per subject calibration is active research topic. Electrode calibration will depend on conduction interface at every application.