External Hordeolum (stye) 

A stye ( hordeolum) is an infection of  the glands inside the eyelid . There are two types of styes, internal hordeolum and external hordeolum. An external  stye is a bacterial infection of the Glands of Zeis and/or Glands of Moll inside the eyelids.   An internal stye  is a bacterial infection of the meibomian glands inside the eyelids. It can cause swollen and pain of the eye lid, sometimes ​changes the vision. It needs to be treated with warm compress and antibiotic. 

       Preseptal Cellulitis

Preseptal cellulitis is an infection of the eyelid typically caused by bacteria. The main symptoms are redness and swelling pain of the eyelid.

The infection need  treated with antibiotics and close monitoring, but it can be serious if left untreated.