Description, causes, prevention, treatment and medicines
Tears are usually associated with crying, often as a result of unhappiness or pain. But our eyes make tears continuously. Tears are important for protecting, lubricating and cleaning the eyes.
Tears are secreted by tiny glands (lacrimal glands) situated under the eyelid above the outer corner of each eye.
They flow across the eye, acting as a lubricant. Their spread across the eye is helped by blinking.
Tears leave the eye by draining into 2 tiny canals, the lacrimal ducts (sometimes called tear ducts), situated near the corner of each eye next to the nose. The 2 lacrimal ducts for each eye join together forming the nasolacrimal duct, down which tears flow into the nose.
When things go wrong with this system one of 2 things may happen: the eye may become watery or it may become dry.
Watery eyes are sometimes due to excessive production of tears. This can happen as a result of wind and glare, or an allergic stimulus. But usually watery eyes are due to a problem, usually a blockage, in the drainage system. Blockage of the tear ducts is common, especially in tiny babies. This may lead to recurring infections of the eye’s surface layer (conjunctivitis).
In children, regular massaging of the area between the eye and nose may unblock the tear ducts. Sometimes they need probing or syringing by a medical professional to be cleared. Very rarely an operation is needed to allow tears to drain into the nose.
Dry eyes are common with increasing age, when tear production is reduced. Hormonal changes after menopause are a common cause in women. Certain diseases, such as rheumatoid arthritis, and certain drugs such as diuretics (‘fluid tablets’) are associated with dry eyes.
People with dry eye usually notice an uncomfortable ‘gritty’ feeling in the eye. This can be relieved by frequent use of drops, or ‘artificial tears’, which can be used as often as necessary. Sometimes ointment inserted at night, when tear production is lowest, also helps.