Babies blink lesser than adults. (Source: Getty Images)
You may have noticed that your newborn is hardly blinking. And a lot of studies in the past have analysed why.
A 2010 study titled Optometry and Vision Science by Leigh F Bacher states that spontaneous eye-blinking rate is less than four times per minute in human babies. The rate gradually increases to 15-30 per minutes in adulthood.
Why do babies blink less than adults?
There are multiple theories that analyse why babies blink lesser than adults. One such theory is that blinking helps keep the eye lubricated but since babies have smaller eyes and sleep much more than adults, their eyes do not need as much lubrication and hence blink less.
According to Bacher, infants are also exposed to a lot of brand new visual information, which affects their blinking rate. "When you do visually or attentionally demanding things, you tend to blink less," the researcher was quoted as saying in an interview.
Research also suggests that eye blink rate (EBR) is a "non-invasive indirect marker of central dopamine function". "Eye-blinking, to some extent, is related to the baby's brain development. If the levels of dopamine are slightly less, the blinking is lesser," Dr Subhash Rao, consultant paediatrician, Hiranandani Hospital, told Express Parenting.
Does the blinking rate vary in babies?
"Blinking varies from child to child, no doubt, but as the child grows up, the rate of blinking does improve. In some children, it is faster as compared to others, just like other milestones. So, there is no reason to worry," said Dr Rao.
The blinking rate in babies could be an indicator for autism spectrum disorder. According to a study by researcher Warren Jones, Emory University School of Medicine, Atlanta, published in Proceedings of the National Academy of Sciences, blinking can index how engaged people are with what they are looking at. While children without autism are able to respond as per the social context, those in the autism spectrum may often be reacting to physical events after they have already happened.
But blinking cannot be analysed in isolation. Dr Rao clarified, "If your baby is not blinking, could they have autism? Well, no one can tell that. At around one year, if the child is not responding by name or just staring at objects or not being self-indulgent, the symptoms would be subject to further diagnosis. The blink rate could figure among the symptoms but may not be the only one."
Another 2010 study published in The Journal of Nutrition found out that eye blinking rates in infants with iron-deficiency anaemia are lesser. "Lower eye-blink rate in infants with iron-deficiency anaemia is consistent with reduced dopamine function in humans, the study said.