Usually a sty is a harmless eye problems. It looks like a boil or a pimple. It can be formed both inside and outside your eyelid.
From what I have read, besides poor hygiene, the formation of a sty is the result of an infection of the oil glands of the eyelid. This happens because the glands have become clogged.
If it is a mild sty, normally I would wash the affected area with a clean warm face towel. And just let it rupture by itself. Then it will go away after a few days.
This time around my sty appeared to last longer. I could not see any pus formation. After just washing it and treated it with eye-drops for three days with not much result, I bought Terramycin ophthalmic ointment from my neighborhood pharmacy. It cost only RM5(1.53 USD).
It worked wonderfully well. Using a clean cotton stick, I applied the colorless creamy ointment on my sty a few times a day. After applying it for a day, the pain was lessen and with a gentle press with a cotton stick, the yellow pus oozed out. Then I applied the sticky and oily ointment over the reddish area.