Blink

A blink or blink is a fast, usually involuntary and unnoticed expiring closing and opening of the eyelids ( blink reflex ), which serves as a permanent wetting of the cornea with tears primarily the maintenance of the tear film and the eye protects against dehydration. In addition, be wiped away and removed through the tear duct to the regular blink on the eye came fine particles.

Basics

A person blinks per minute about 10 to 15 times, so every 4 to 6 seconds, and this happens over a period of an average of 300 to 400 milliseconds. The caused by the closing of the eyelids dark phase is not consciously perceived, as the visual perception is suppressed in the relevant areas of the brain just before the blink.

According to a small study from 2008 women blink not only faster than men, but with about 19 more often compared to 11 blinks per minute. Older women also blink more often than young.

Disorders

Increased or sustained Blink is (often along with other involuntary and often associated with pain wrong movements in the face and / or neck muscles with grimacing and deformities of the head) seen in dystonia disorders.

Frequent blinking may also be the result of a tic disorder.

Variety poor screen work leads to a report by the University Eye Clinic Tübingen in the journal The ophthalmologist to stare at the screen with a decrease in blink frequency from 9.7 to 4.3 per minute. In contrast to a few, but long pauses frequent but brief interruptions of work are also eye medically recommended at the computer for a few minutes in order to prevent a particular dry eye syndrome.

In the unconscious patient speaks spontaneous blink of an intact reticular formation in the bridge area; in response to a light or sound stimulus for an at least partial preservation of the visual and auditory pathways.

Frequently occurs when an endocrine ophthalmopathy a rare blink on, calls the one Stellwag characters and can be quantified with blinks per minute.