Narrative review: Do spontaneous eye blink parameters provide a useful assessment of state drowsiness?

Most objective drowsiness measures have limited ability to provide continuous, accurate assessment of drowsiness state in operational settings. Spontaneous eye blink parameters are ideal for drowsiness assessment as they are objective, non-invasive, and can be recorded continuously during regular activities. Studies that have assessed the spontaneous eye blink as a drowsiness measure are diverse, varying greatly in respect to study design, eye...