A red bump inside the corner of the eye can be caused by a tear frenulum, a wheal, or a pterygium. 1. Lacrimal caruncle: the normal tissue of the eye, located at the inner corner of the eye. In its normal form, it should be a flesh-like elevation, which is a metamorphic skin tissue between skin and mucous membrane. 2. wheal: an acute inflammatory condition caused by purulent bacteria entering the glands of the eyelid, which can lead to bumps at the corners of the eyes. 3. Pterygium: a chronic proliferation of the conjunctiva and subconjunctival tissues in the form of red bumps caused by chronic inflammation over a long period of time, as well as daily irritation. When there is a red pimple inside the corner of the eye and accompanied by other symptoms, you should go to the hospital in time to clarify the cause and then targeted treatment.