P you might possibly offer definitions of key terms, although it is often a good idea to save this until you use these words in the essay and you can then offer definitions when they become relevant to the reader rather than hitting them with all of the definitions in a big, boring, confusing mass right at the start.
Thygeson's superficial punctate keratopathy (TSPK; also Thygeson Superficial Punctate Keratitis) is a disease of the eyes. The causes of TSPK are not currently known, but details of the disease were first published in the Journal of the American Medical Association in 1950 by Phillips Thygeson-after whom it is named. patient with TSPK may complain of blurred vision, dry eyes, a sensation of having a foreign body stuck in the eye, photophobia (sensitivity to bright light), burning sensations and watery eyes.
Tears leave the surface of the eye in one of two ways, either by evaporation or drainage through the lacrimal puncta and tear drainage system into the nose. Theoretically, the fewer tears that drain into the nose, the more moisture remains on the surface. So punctal plugs are used to block drainage into the nose. Depending on the type of dry eye problem you have, our eye doctors may use a different type of punctal plug. The two main types are temporary or permanent punctual plugs. The permanent plugs are made of a silicone substance and the temporary plugs are made of dissolvable collagen. Our dry eye doctors may decide to place a temporary plug in your eye prior to selecting a permanent punctal plug. Most patients have no problems with punctal plugs and cannot even feel them in the eyes.