Eye Openness (EO) is a new eye tracking signal developed by Tobii for researchers, the EO represents a measure of the largest sphere that can fit between the upper and lower eyelids. The EO signal provides the basis for accurate eyelid movement detection, including different types of blinks.

EO in Cognitive and Physiological processes

  1. The EO signal has been mainly used to detect driver drowsiness — the major risk factor for driving accidents.
  2. Eyelid movement provides several metrics such as
    • Percentage of eye closure (PERCLOS)
    • Eyelid closing/opening duration and speed
    • Blink rate
  3. With the help of EO signal it is now possible to assess various eyelid movement related dysfunctions such as dry eye disease, progression of Alzheimer’s Disease, blepharospasm, and ptosis.
  4. The EO signal can also help identify clinical conditions characterized by aberrant dopamine levels, such as Parkinson’s or schizophrenia.

Using Eyelid Movements to Detect Eye-Tracking Errors

  1. Eyelid movement-related artifacts cause significant data alterations in the eye tracking data. But now with the new EO signal, it is possible to accurately estimate blinks and obtain a correct pupil diameter measurement.
  2. Eyelid movements can also interfere with saccades. Eye openness (EO) signal can help researchers detect eyelid activity and reduce errors in measuring saccades.
  3. Eyelid movements are source of artifacts also in electroencephalographic (EEG) data. Every EEG recording is contaminated by artifacts emerging from blinks, eyelid saccades, and post-saccadic eyelid movements.
  4. But now the Eyelid movement detection with the new EO signal had ease eyelid artifacts identification, especially in scenarios where electrooculographic (EOG) measurements are unavailable.

Eye openness signal is currently available in Tobii Pro Spectrum (1200 Hz) and Tobii Pro Fusion (250 Hz) and with Tobii Pro Lab Software we can record the data, visualize it during replay, and export the raw data as well as several metrics based on eye openness.

If you’d like to dive deeper into any particular study or point, feel free to ask us at parag@tidentech.com or tidentech@gmail.com or call us on +91 9987442274.