Blinking

[citation needed] It is an essential function of the eye that helps spread tears across and remove irritants from the surface of the cornea and conjunctiva.

Eyelashes are hairs which grow from the edges of the upper and lower eyelids that create a line of defense against dust and other elements to the eye.

The correlation between human eyelid blink behavior and psychological stress was also demonstrated by means of a laboratory study.

The duration of a blink is on average 100–150 milliseconds according to UCL researcher[10] and between 100 and 400 ms according to the Harvard Database of Useful Biological Numbers.

Greater activation of dopaminergic pathways dopamine production in the striatum is associated with a higher rate of spontaneous eye blinking.

For example, compared to an aquatic environment, in a terrestrial environment, the corneal cells must be kept moist such that vital substances like oxygen can more easily diffuse into them, detritus may adhere to the eye in dry conditions, and objects may move towards the eye at faster and more dangerous speeds in air than in water.

This type of blinking is conducted in the pre-motor brain stem and happens without conscious effort, like breathing and digestion.

A reflex blink occurs in response to an external stimulus, such as contact with the cornea or objects that appear rapidly in front of the eye.

Infants also get a significant amount more sleep than adults do and, as discussed earlier, fatigued eyes blink more.

Computer vision syndrome can be prevented by taking regular breaks, focusing on objects far from the screen, having a well-lit workplace, or using a blink reminder application.

Studies suggest[26] that adults can learn to maintain a healthy blinking rate while reading or looking at a computer screen using biofeedback.

For example, excessive blinking may help to indicate the onset of Tourette syndrome, strokes or disorders of the nervous system.