Question

Why do our eyes blink?

Answer 1

It is needed to clear away dust particles and spread lubricating fluids across the eyeball. Every time you blink, your eyelids spread a wingspantail of oils and mucous secretions across the surface of the eye to keep your globes from drying out. Blinking also keeps eyes safe from potentially damaging stimuli, such as bright lights and foreign bodies like dust.

Answer 2

Keep in mind this also replaces all forms of water on the eye, etc, etc. There's a much deeper explanation than just cleansing and moistening, though.

We blink much more often than we need to, though. Infants blink once every minute. When we grow up we blink 10-15 times a minute. When we're stressed we blink as much as 30-40 times a minute. What does this mean? The reason we blink has a lot more to do with psychology than necessity. When reading something interesting or doing something intriguing we blink much less. It's not unique to visual entertainment, though. We blink much less when listening to material, too.

In theory, one who is more stressed whether it be long term or at the immediate moment, will blink more. This also occurs when one is sleep deprived. They feel a psychological need to blink more.

Blinking more than usual can even result in a nervous tic. When your stress occurs often causing you to blink frequently, your body can get used to this hence making you blink to the point your body gets used to it.

Answer 3

http://en.wikipedia.org/wiki/Blink

Answer 4

http://www.livescience.com/32189-why-do-we-blink.html