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Normal secretion of tears.
Excessive secretion of tears, as in weeping.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



in mammals, including man, the secretion of tears by the lacrimal gland. A continuous process that ceases only during sleep, lacrimation is a reflex that occurs when the cornea becomes irritated or dry. Blinking causes tears to be conducted to the inner canthus, where the lacrimal points and canaliculi, lacrimal sac, and nasolacrimal canal commence.

Man normally secretes 0.5–1 milliliters of tears daily. Lacrimation may intensify (hypersecretion) when an individual experiences such emotions as pain, anger, and joy, and when irritation occurs at the branching of the trigeminal nerve. Lacrimation decreases sharply (hyposecretion) with certain eye diseases, for example, trachomatous xerosis.


Odintsov, V. P. Kursglaznykh boleznei, 5th ed. Moscow, 1946.
Tikhomirov, P. E. Patologiia i terapiia slezootvodiashchikh putei. Leningrad, 1949.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
If a clinician has limited time for a patient interview, he or she should ask about lacrimation, facial swelling, and conjunctival injection as uAS.
Patients were asked to report any change in their perception of pain, discomfort, foreign body sensation, photophobia, and lacrimation, giving yes or no answer.
Jain SR et al found that 74.8% understudies experienced excessive lacrimation as the first occurring symptom.
The most common symptoms were hyperemia, lacrimation, foreign body sensation, discharge, and burning, in decreasing order.
Caption: FIGURE 1: SUNCT-related right eye conjunctival injection and lacrimation are visible, with additional right ptosis related to partial cranial nerve VII palsy.
An EKC case was defined as an ophthalmologist-diagnosed acute nonbacterial eye disease, characterized by conjunctival inflammation and lacrimation with >2 of the following symptoms: foreign body sensation, light sensitivity, eye pain, or conjunctival edema.
The birds were monitored for the duration of the study for any side effects, including ocular irritation (lacrimation, blepharospasm, conjunctival hyperemia, chemosis), local or systemic muscle paralysis (eyelid, wings, legs, neck), and respiratory distress.
On the basis of clinical examination, the calves diagnosed with abnormal sound in lung auscultation, dyspnea, cough, nasal discharge, anorexia, depression, hyper salivation, lacrimation and accessible mucosal surface lesions were selected for pneumonia group (Group P, n = 20); the ones diagnosed with anorexia, depression, accessible mucosal surface lesions and diarrhea formed enteritis group (Group E, n = 20) as the calves with lung auscultation, dyspnoea, cough, nasal discharge, anorexia, depression, hyper salivation, lacrimation, accessible mucosal surface lesions and diarrhea were chosen for the Pneumoenteritis group (Group PE, n = 20).
When there is expression of muscarinic overstimulation due to excess acetylcholine at muscarinic acetylcholine receptors symptoms of visual disturbances, tightness in chest, wheezing due to bronchoconstriction, increased bronchial secretions, increased salivation, lacrimation, sweating, peristalsis, and urination can occur [16,36].
They showed normal lacrimation salivation and corneal reflex.
(36) Further, the addition of fluorescein to the ocular surface may itself influence the measurement, as application may induce reflex lacrimation which artificially lengthens FBUT.
The animals were observed for general behavioral changes and signs of toxicity and mortality such as alertness, grooming, touch response, pain response, tremors, convulsions, righting reflex, gripping strength, pinna reflex, corneal reflex, pupils, urination, salivation, skin colour, lacrimation, and hyperactivity continuously for 1h after treatment, then intermittently for 4h, and thereafter over a period of 24 h.