A stye is a visible infection that appears at the edges of an eyelid. Its appearance can vary somewhat, but it is harmless to your vision. Symptoms include a noticeable swelling, some discomfort and tenderness in the affected area.
Most styes heal without treatment, although the application of a hot compress can help. Unlike a pimple, however, styes cannot be manually ruptured and drained. Antibiotic ointments are available for recurring cases.