A hordeolum is often referred to as a sty . It is a plugged and infected oil gland in the eyelid.  Because the tissue is swollen from the infection they tend to be very tender.

After a period of time the body kills the bacteria but often leaves behind a non tender hard nodule which we call a chalazion .

The treatment for both conditions is warm compresses. In some cases systemic antibiotics are needed in the acute hordeolum phase. If the warm compresses do not resolve the chalazion completely surgical excision may be required.