How Fast Is a Blink of an Eye?

By Emily Jacobson; Updated April 24, 2017
Involuntary blinks are fast, but voluntary winking can be slow.

The average duration for a single blink of a human eye is 0.1 to 0.4 seconds, or 100 to 400 milliseconds, according to the Harvard Database of Useful Biological Numbers. For purposes of comparison, the tick sound made by a clock lasts about one second. So it would be possible to blink three times during a single tick of a clock.

Blinking, Winking and Nods

Researchers measure changes in blink duration to study fatigue.

Blink duration and blink rate -- the number of times a person blinks per minute -- are controlled by a central mechanism in the brain. This mechanism can be affected by medications, fatigue, disease, illness and even the age of an individual. As such, both blink duration and blink rate may slow down when a person is tired, sick or using sedative drugs. Alternatively, blink rate and blink duration may speed up when using stimulant drugs like caffeine. This means that the duration of a blink can vary, not only from one individual to another, but from blink to blink.

About the Author

Emily Jacobson has been working in online media and publishing for more than two decades. Her articles have been featured on America Online and the Maxwell Institute. She specializes in articles related to science, health and nutrition. Jacobson holds a Bachelor of Science in food science and nutrition.