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tear

Secretion that cleans and lubricates the eyes

EntityQ76469

Also known as tears · tearing · tear fluid

Subclass of: body fluid

Overview

From Wikipedia, the free encyclopedia · Read full article · Text CC BY-SA 4.0

Tears are a transparent fluid secreted primarily by the lacrimal glands found in the eyes of all land mammals. According to the mode of production, tears are classified into four types: basal, closed eye, emotional, and reflex. The basal rate of tear secretion is ~0.5–2.2 μL/min, and irritation can increase secretion by up to ~100-fold, reaching ~300 μL/min. Tears are made up of water, electrolytes, proteins, lipids, and mucins that form layers on the surface of eyes. The four types of tears differ significantly in their composition.

Overview

All data

49 statements · 24% with external sources · numbers in brackets are citations

Produced by: lacrimal apparatus
Location: eye
Subject has role: cleaning
Members / parts: water
sodium chloride
Facet of: crying
Unicode character: 💧

On other databases

40 identifiers linking tear across the web's reference databases

Data quality

statements

24%

externally sourced

Source last edited October 14, 2026. AIDB refreshes this page daily.

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AIDB. (2026). tear (Q76469). Retrieved from https://aidb.si/e/tear-Q76469