In humans the average duration of a single eye blink is 0.1 second, additionally the time between blinks is generally around 2.8 seconds. It also takes one photon of light to excite a rod in the retina of the eye. Why list this information? Well it illustrates some of the many processes and functions that have been quantified in Biology.
I found these numbers and more whilst looking for the turnover rate of Cytochrome P450 (CYP450) enzymes. This family of isoforms are responsible for oxidative metabolism and govern the majority of drug metabolism observed. How did I become distracted by the physiology and function of the eye? I happened to stumble across a wonderful website dedicated to establishing a database of numbers in biology.
The BioNumbers database was started in 2007 by Ron Milo, Paul Jorgensen and Mike Springer. Its stated aim is to enable researchers to find in one minute any useful molecular biology number that could be important for their research. It is also an enjoyable way to while away a coffee break. By the way, I found the turnover rate for CYP450 enzymes in BioNumbers, it is between 0.96 and 4.33 days!