Studies which have defined the duration of a blink are scarce. Stern, Walrath, and Goldstein (1984) distinguished endogenousblinks from non-blink closures which are associated with sleep onset for instance. Endogenous blinks are characterizedby (i) the time from initiation of the lid movement to full eye closure which takes generally around 100 ms, (ii) the periodduring which the vision is occluded which lasts at most 300 ms, and (iii) the full reopening phase lasting around 100 ms.Capitalizing on this, it was assumed that the longest endogenous blinks last 500 ms. Consequently, eye closure durationgreater than 500 ms were considered non-blink closures and were excluded from our blink analysis.