@article {1351177, title = {Blink patterns and lid-contact times in dry-eye and normal subjects}, journal = {Clin Ophthalmol}, volume = {8}, year = {2014}, month = {2014}, pages = {869-74}, abstract = {PURPOSE: To classify blinks in dry eye and normal subjects into six subtypes, and to define the blink rate and duration within each type of blink, as well as the total lid-contact time/minute. MATERIALS AND METHODS: This was a single-centered, prospective, double-blind study of eleven dry-eye and ten normal subjects. Predefined subjects watched a video while blinks were recorded for 10 minutes. Partial blinks were classified by percentage closure of maximal palpebral fissure opening: 25\%, 50\%, 75\%. Complete blinks were characterized as full (\>0 seconds), extended (\>0.1 seconds), or superextended (\>0.5 seconds). The mean duration of each type of blink was determined and standardized per minute as total lid-contact time. RESULTS: Total blinks observed were 4,990 (1,414 normal, 3,756 dry eye): 1,809 (50.59\%) partial and 1,767 (49.41\%) complete blinks among dry-eye subjects versus 741 (52.90\%) partial and 673 (47.60\%) complete blinks among normal subjects. Only superextended blinks of >=0.5-second duration were significantly more frequent in dry-eye subjects than normals (2.3\% versus 0.2\%, respectively; P=0.023). Total contact time was seven times higher in dry-eye subjects than normals (0.565 versus 0.080 seconds, respectively; P\<0.001). Isolating only extended blinks (\>0.1 second), the average contact time (seconds) was four times longer in dry-eye versus normal subjects (2.459 in dry eye, 0.575 in normals; P=0.003). Isolating only superextended blinks (\>0.5 seconds), average contact time was also significantly different (7.134 in dry eye, 1.589 in normals; P\<0.001). The contact rate for all full closures was 6.4 times longer in dry-eye (0.045 versus 0.007, P\<0.001) than normal subjects. CONCLUSION: Dry-eye subjects spent 4.5\% of a minute with their eyes closed, while normal subjects spent 0.7\% of a minute with their eyes closed. Contact time might play a role in the visual function decay associated with increased blink rates.}, issn = {1177-5467}, doi = {10.2147/OPTH.S56783}, author = {Ousler, George W and Abelson, Mark B and Johnston, Patrick R and Rodriguez, John and Lane, Keith and Smith, Lisa M} }