Tears, which cover entire eyeball or a preocular, surface which moist the eye, lubricates the eye and keeps eye far from certain kind of dryness including smoke, dust. Tears are some kind of human natural response also when crying. It may be due to sadness or may be joy, grief & frustration too.
Researchers have found that crying is not the sign of weakness, infact it gave the restful or a soothing effect and some kind of reducing distress, helps to relieve pain, can helps babies to sleep better, kill bacteria, keep eye clean & improves the vision on every blink.
TYPE OF TEARS
BASAL TEAR – These tear are protein rich antibacterial liquid that helps to keep eye moist.
REFLEX TEAR – These tear releases to flush the irritants like wind, dust, smoke, onions & protect the eye.
EMOTIONAL TEAR – It varies with the range of human emotion, these tears contains the level of emotion, stress, joy, grief.
SALINITY OF TEARS
Tears are salty in taste, due to presence of salts of sodium & potassium in it.
DRAIN OF TEARS
It starts from the secretion of lacrimal gland then it moist whole of the eye and when blink it goes on to the upper and lower puncta of same eye from here with the help of upper and lower canaliculi it drained into the nasolacrimal duct (NLD). This whole process is called the lacrimation.