Why Do We Blink?
Blinking is the action of closing and opening our eyes. Itâ€™s something that we do approximately every 4-10 seconds without even thinking about it. And although it is an involuntary reflex, we can make ourselves blink more or less if we choose to.
But why do we need to blink?
Primarily, we blink in order to lubricate our eyes. Each eye has a pair of glands called the lacrimal glands. These carry tears to the eye which are washed across the surface of the eyeball, the conjunctiva, each time we blink, keeping the eye healthy.
They then drain away through a passage into the nose, which explains why we sometimes get nasal congestion when we cry. When the eye starts to feel dry it gets cooler and this causes us to blink.
We also blink to clear away any dust or foreign particles that might be on the eye, the eyelashes help with this too by automatically lowering whenever a dust particle approaches our eye so that they can catch it before it gets to the eyeball. The eyelids also close when the eye senses excessive light, to protect the eye. This is something that our bodies hardly even register; the brain is able to ignore the temporary darkness.
You might have noticed that your eyes get more tired when youâ€™ve been looking at a computer screen for a long time, or have been concentrating on a certain task like sewing. This is because the brain â€œforgetsâ€ to blink, resulting in our eyes becoming dry and feeling tired. We tend to blink more in smoky atmospheres, or even when wearing contact lenses.
We also blink more when weâ€™re nervous or tense. This suggests that the reasons for blinking are not only biological, but psychological too. A study by Tamami Nakano of Osaka University showed that we blink more when weâ€™re not interested in a task. Nakano suggests that when we blink a lot during an activity that requires less attention, weâ€™re actually resetting our brains, almost like rebooting a computer.
There are also studies that suggest that increased blinking can be linked to deception. There is a school of thought that says that a person who is lying blinks more, which fits in with the theory that we blink more when nervous or tense. We might be able to deceive somebody on the surface, but itâ€™s almost impossible to hide our bodyâ€™s natural reflexes.
Other researchers think that we are more likely to blink less when we are lying. They say that because we need to concentrate more on what weâ€™re saying to someone when weâ€™re lying, we forget to blink, rather like when weâ€™re concentrating on a certain task, as mentioned earlier.
It seems that just observing blinking is not a reliable way to tell if someone is lying to you; you need to look at other body language too.
We not only blink at different frequencies, depending on how weâ€™re feeling, but each blink is different. Sometimes we blink quickly, other times we blink slowly. Itâ€™s also interesting to note that adults blink more often than children.
This could be because their eye openings are smaller meaning that they donâ€™t need as much lubrication, or there could be deeper psychological reasons. Needless to say itâ€™s yet another example of how intricate the workings of our body are.
Nothing in this blog post is to be construed as medical advice, nor is it intended to replace the recommendations of a medical professional. For specific questions, please see your eye care practitioner.
Jonathan Scarlet works for CooperVision and has a passion for learning and writing about science and anatomy. In his spare time he likes to travel, cook, and spend time with his family. Read more about some of CooperVisionâ€™s contact lens and eye care related articles here.