When the base of an eyelash gets infected, it causes localized swelling, redness, and discomfort. The swelling may shut the eye almost completely. The sty usually lasts a few days, after which it pops spontaneously or decreases in size. Place a warm compress on the area to reduce discomfort and hasten healing, but I don’t recommend antibiotic creams, which have little effect.
In rare cases, some kids have small white bumps at the margin of the eyelid. Known as chalazions, they can appear at any age, last for months or years, and require no treatment unless they are inside the eyelid and cause irritation during blinking. In this unusual event they should be removed.