Blink

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Blinking in slow motion

A blinking or winking is a fast, usually involuntary and unnoticed expiring closing and opening the eyelids ( blink reflex ) that the first of maintaining tear film as a permanent wetting of the cornea with tear fluid used and the eye protects against dehydration. In addition, with the regular blink of an eye, fine particles that have reached the eye are wiped away and transported away via the tear duct .

Basics

A person blinks about 10 to 15 times per minute, i.e. every 4 to 6 seconds, and this happens over an average of 300 to 400 milliseconds. The dark phase caused by the eyelid closure is not consciously perceived, as the visual perception in the responsible areas of the brain is suppressed shortly before the blink. The blinking of the eye is usually synchronous, ie on both sides and simultaneously. But it is possible for almost everyone to willingly close the eyelids of just one eye.

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

Disruptions

Increased or permanent blinking can be seen in dystonia diseases (often together with other involuntary and often painful incorrect movements in the area of ​​the face and / or neck muscles with grimacing and misalignments of the head).

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

Variety arms VDU leads according to a report of the University of Tübingen said in the journal , the ophthalmologist to stare on the screen with a decrease in the frequency of blinking of 9.7 to 4.3 per minute. In contrast to a few but long breaks, frequent but short interruptions to work on the computer for a few minutes are also recommended by the ophthalmologist, in particular to prevent dry eye syndrome .

In unconscious patients, spontaneous blinking suggests an intact reticular formation in the bridge area ; as a reaction to a light or sound stimulus for at least partial preservation of the visual or auditory pathways .

Often with endocrine orbitopathy, a rare blinking of the eye occurs, which is known as the Stellwag sign and can be quantified with blinking of the eye per minute.

Web links

Wiktionary: Lidschlag  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ↑ Robert A.Moses (ed.): Adler's Physiology of the eye clinical application . Mosby, 1981, chap. 1, pp. 1-15.
  2. ^ Bristow D, Haynes JD, Sylvester R, Frith CD, Rees G: Blinking suppresses the neural response to unchanging retinal stimulation . In: Current Biology . 15, No. 14, 2005, pp. 1296-1300. doi : 10.1016 / j.cub.2005.06.025 . PMID 16051173 .
  3. ^ C Sforza, M Rango, D Galante, N Bresolin, VF. Ferrario: Spontaneous blinking in healthy persons: an optoelectronic study of eyelid motion . In: Ophthalmic Physiol Opt. , 2008 Jul, 28 (4), pp. 345-353, PMID 18565090 .
  4. ↑ Vol. 102, p. 805
  5. ↑ Axenfeld, Pau: Textbook and Atlas of Ophthalmology . With the collaboration of R. Sachsenweger u. a. Gustav Fischer Verlag, Stuttgart 1980, ISBN 3-437-00255-4