Traditional Culture Encyclopedia - Weather inquiry - What is the reason why eyes always shed tears?
What is the reason why eyes always shed tears?
Human tears are secreted by the lacrimal gland, in which the main lacrimal gland is the reflex secretor. When stimulated by factors such as pain, cold and obvious emotional changes, the secretion of tears increases. Therefore, when stimulated by cold air, it can reflexively cause excessive secretion of the main lacrimal gland. At the same time, the skin and muscles around the face and orbit contract after cold stimulation, which oppresses the lacrimal passage. Tears are prevented from being discharged from the nasal cavity and forced to flow out from the corner of the eye, so tears flow freely.
Generally speaking, under normal circumstances, this phenomenon is short-lived, and it will soon disappear when the body adapts.
When suffering from trachoma, ciliary inversion, keratitis, keratomalacia, uveitis, ametropia and other eye diseases, conjunctiva congestion, corneal damage. At this time, the sensitivity of eyes to external stimuli is enhanced, and the phenomenon of tears in the wind is more obvious. If the nasolacrimal duct is normal and unobstructed, even if there are tears in the wind, it is not always lasting. Only when there are tear diseases such as chronic dacryocystitis and lacrimal duct stenosis at the same time, excessive tears can not be discharged through nasolacrimal duct in time, and long-term windward tears will occur.
If there are tears in the wind, it is a clear signal to people. To attract attention, we should go to the hospital as soon as possible to find out the specific cause and receive corresponding treatment. For trachoma, acute and chronic conjunctivitis, various effective antibiotic eye drops can be dropped, while patients with keratomalacia should be supplemented with vitamin A, including taking vitamin A and eating more foods rich in vitamin A, such as carrots, tomatoes, spinach, animal liver, eggs and so on.
When ametropia occurs, you should check your eyesight, optometry and wear appropriate glasses in time. For nasolacrimal duct obstruction or stenosis, nasolacrimal duct irrigation or nasolacrimal duct probing is needed.
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