Ulcer

Cornea is the window through which we see the world. A corneal ulcer is an open sore in the cornea, the clear and round front part of the eye through which light passes.
Most of us have had a tryst with mouth ulcers at some point in our lives. They are not only very painful, but are easily transmitted from person to person, causing distress to the affected individual.
A peptic ulcer is a sore on the lining of the stomach or duodenum. These are the parts of the gut where acid bathes the surface. One cause of peptic ulcer is bacterial infection by Helicobacter pylori, but some ulcers are also caused by long-term use of non steroidal anti-inflammatory agents (NSAIDs), like aspirin and ibuprofen. In a few cases, cancerous tumors in the stomach or pancreas can also cause ulcers.