“…In the clinical examination of the external eye, it will be a routine procedure for the patient to be seated at a slitlamp with open eyes and directing their gaze to the distance whether this be for assessments of tear flow, tear film stability, tear film lipid layer or tear meniscus height, for example. The same applies to contact lens wear adaptation, comfort issues and spontaneous blink activity, where measurements of the SBR are been carried out in the primary gaze . Whether as part of routine eye examination or as the experimental set up in studies on spontaneous blinking, a number of investigators have opted for recording blink activity, while subjects were seated with their head supported on some type of chin and forehead rest .…”