A sty

In most cases, a sty doesn't require specific treatment. A sty typically goes away on its own.

For a sty that persists, your doctor may recommend treatments, such as:

Antibiotics. Your doctor may prescribe antibiotic eyedrops or a topical antibiotic cream to apply to your eyelid. If your eyelid infection persists or spreads beyond your eyelid, your doctor may recommend antibiotics in tablet or pill form.
Surgery to relieve pressure. To treat a pus-filled sty that won't rupture or burst on its own, your doctor or ophthalmologist may choose to lance and drain the sty to relieve pain and pressure.

Until your sty goes away on its own, try to:

Leave the sty alone. Don't try to pop the sty or squeeze the pus from a sty. Doing so can cause the infection to spread.
Place a warm washcloth over your closed eyes. To relieve pain, run warm water over a clean washcloth. Wring out the washcloth and place it over your closed eye. Re-wet the washcloth when it loses heat. Continue this for 10 or 15 minutes. Repeating this several times each day may encourage the sty to drain on its own.
Keep your eye clean. Don't wear eye makeup until the sty has healed.
Go without contacts lenses. It's possible for your contact lenses to become contaminated with bacteria associated with your sty, so plan to go without contacts until your sty goes away.