Human Body

Nerves and Senses

How often does a person blink?

The original bifocal lens was invented in 1784 by Benjamin Franklin (1706–1790). At that time, the two lenses were joined in a metallic frame. In 1899, J.L. Borsch welded the two lenses together. One-part bifocal lenses were developed in 1910 by researchers at the Carl Zeiss Company.

The rate of blinking varies, but on average the eye blinks once every five seconds (12 blinks per minute). Assuming the average person sleeps eight hours a day and is awake for 16 hours, he or she would blink 11,520 times a day, or 4,204,800 times a year. The average blink of the human eye lasts about 0.05 seconds.

