(Continued)
Sty
I might have mentioned before that the great designer was at his/her constructive best when the eye was being put together. Every little consideration was taken into account. For example, we know that the production of fluids to moisten the exposed surface of the eye is continuous. If, because of emotional stress, say, there is a profusion of fluid production from some special (lachrymal) glands, then we have tears overflowing. Of course, there are canals to lead off the excess fluid into the nostrils (that’s why we sniffle when we cry).
Under normal conditions, the fluids that are secreted are well catered for by these run-off canals/ducts. However, there is another mechanism to prevent the overflow of liquid secretion. There is an oily barrier to prevent the overflow of secretion, leading the latter to the drainage ducts. This oily barrier is in the form of a secretion which comes from several glands that have their exit aperture on the edge (margin) of the eyelids.
These glands secrete an oily material which prevents the lubricating liquid from overflowing the eyelids. Sometimes, however, these glands can become infected or micro-particles of dirt (eg) can physically constrain their function. They then swell and become inflamed (red). Pus develops in