Styes can be messy with a pus-filled swelling. It is a common bacterial
eye infection and it can also be contagious. What are the causes of hordeolums or stye? It can be the result of blocked and infected glands in your eyelid. Oftentimes, it is contaminated by a dirty finger that touches the eye area. When styes become painful, it is because of meibomian, meaning the gland that allows eyelid lubrication is blocked.