1. How Long Is a Blink, and How Often Do We Blink?
A blink is very fast. On average, one blink lasts between 100 and 150 milliseconds, or about 0.1 to 0.15 seconds [5]. Most people blink about 20 times per minute [2]. If you are awake for 16 hours, that is about 19,200 blinks. If each blink takes 0.1 seconds, that is 1,920 seconds, or about 32 minutes. If it takes 0.15 seconds, it is 2,880 seconds, or 48 minutes. So, you spend about 30 to 50 minutes a day with your eyes closed just for blinking. This is an estimate based on multiplying the numbers from the sources, not a direct measurement.
The number of blinks changes a lot depending on your age and what you are doing. Infants blink only 2 to 5 times per minute. Children and teenagers blink 4 to 18 times. Adults blink 10 to 30 times [5]. Since blinking takes up so much time, something important must be happening on the surface of your eyes. What is it?
2. The Three Main Reasons We Blink
According to eye doctors, there are three main reasons we blink [1]. First, blinking wipes away dust and debris from the eye’s surface. Second, it spreads tears evenly across the eye. Third, it helps drain excess tears.
You can think of your eyelids like the wipers on a car. Car wipers clear dirt from the windshield and spread water to keep the view clear. Blinking works similarly: your eyelids sweep across your eye, wiping away dust and spreading tears. However, blinking also has the extra job of helping tears drain away.
Tears are very important for this process. The way tears spread has a surprisingly detailed structure.
3. What the Tear Film Is and the Three Parts It Is Made Of
Tears are a salty liquid that keeps the surface of your eye moist. They also carry oxygen and nutrients to the cornea, which is the clear front part of the eye [3]. Any extra tears drain through a tiny hole called the punctum, then travel through thin tubes into your nose [3].
The tear film on your eye is made of three thin layers: a mucin layer, a liquid layer, and an oil layer [2]. The outermost layer is oil. Its job is to stop the tears from evaporating [4]. Each time you blink, your eyelid spreads this film over the eye, which helps prevent evaporation [4]. We will not look at the detailed structure of the oil layer in this article.
So, what happens to this film if you blink less?
4. Three Types of Blinks: Spontaneous, Reflex, and More
There are three types of blinks [5]. First, there are spontaneous blinks, which happen without you thinking about them. Second, there are reflex blinks, which happen because of a stimulus like light. Third, there are voluntary blinks, which you do on purpose.
Reflex blinks protect your eyes from wind, dust, insects, and bright light. Your eyelids close quickly and physically cover the eye to keep it safe [3].
To summarize, blinking has two main functions: it moistens the eye with tears, and it protects the eye from danger. If this movement happens less often, problems might occur.
5. Why Looking at Screens Makes You Blink Less
When you concentrate on a computer or a book, your blink rate often drops. This can make your eyes feel dry or make bright light feel more glaring [1]. The Japan Ophthalmological Society explains that long periods of staring at screens reduce blinking, which makes tears evaporate from the eye’s surface more easily [6].
A study reported in 2025 looked closely at this relationship. Young adults with dry eye symptoms participated. Their natural blink rate was about 28 times per minute. When researchers asked them to blink only 10 times per minute, the time it took for their tear film to break down became significantly shorter. For these participants (45 people aged 19 to 28), blinking at least 20 times per minute was the threshold to keep the tear film stable [4].
It is important to note who was studied. These results are from young adults with dry eye symptoms. They may not apply directly to children.
6. What the Brain Does with Blinking When Watching Video Cuts
Blinking might not just be about your eyes. Researchers at Osaka University and other institutions studied the brain activity of people watching videos [7]. They found that right after a blink, activity in the dorsal attention network (the area that helps you focus) dropped for a moment. At the same time, activity in the default mode network (the area active when you are daydreaming or thinking inwardly) rose for a moment. Simply dimming the video did not cause these same changes [7].
The researchers interpret this result as a sign that blinking might help the brain briefly switch attention [8]. This idea assumes that blinks happen more often at breaks in videos, such as scene changes. However, this is a hypothetical interpretation. We cannot yet say for sure that "blinking lets the brain rest."
7. How to Check Your Own Blinking
If you want to learn more, try counting your own blinks for one minute. Compare how often you blink while reading a book versus when you are looking out the window and daydreaming. Be careful: if you focus too much on counting, your blinking pattern might change. So, treat the numbers as a rough guide and have fun with it.
When you watch videos, you might also try to notice if you blink when the scene changes. But remember, if you worry too much about it, your blinking might not be natural anymore.
If you want to read more, try looking up Japanese ophthalmology resources, such as the Japan Ophthalmological Society’s guide on "Computers and Eyes."