A patient’s blink rate is an important parameter when assessing their ocular health, especially during a dry eye evaluation. For example, research shows digital device use is linked with lower blink rates, and thus increased dry eye parameters.1 But it can be a moving target, according to new research. An investigator based in Glasgow has determined that clinicians need to keep in mind how long a patient has been in their chair when performing a slit lamp‐type assessment of eye blink activity—patients’ spontaneous blink decreased the longer they sat behind the slit lamp. However, it is not obviously related to visual blur in ametropic individuals.2
The study made video recordings of eye blink activity of 85 young adults who were either emmetropic or spectacle wearers with refractive errors between -8.25D and +8.25D. After an initial adjustment period that took anywhere from one to two, participants were recorded for five minutes while seated with forehead and chin support and directing their gaze at a high‐contrast target. The mean spontaneous eye blink rate values over five minutes were 13.4±3.1 blinks/minute, ranging from 7.4 to 20.8 blinks/minute.2
The researcher only recorded 39 incomplete blinks in the total of 5,704 recorded. He noted a progressive decline in the average spontaneous eye blink rate values, with 70.6% of the participants exhibiting a higher spontaneous eye blink rate value in the first minute compared with the fifth minute.2
The inter‐participant variability in spontaneous eye blink rate also progressively declined over time. Still, the study noted no detectable difference in either averaged values or the variability in spontaneous eye blink rate in relation to refractive error.2
1. Argilés M, Cardona G, Pérez-Cabré E, Rodríguez M. Blink rate and incomplete blinks in six different controlled hard-copy and electronic reading conditions. Invest Ophthalmol Vis Sci. 2015;56:6679-85.
2. Doughty MJ. Spontaneous eye blink activity during slit lamp‐based assessments. Clin Exp Optom. August 16, 2020. [Epub ahead of print].