Eyelid problems refer to a variety of conditions that can affect the eyelids, such as styes and sties. A stye is an infection of the eyelid caused by bacteria, which results in a red, swollen bump on the eyelid. Sties are similar to styes, but they are caused by an inflammation of the oil glands in the eyelid. Both conditions can be painful and cause discomfort, but they are usually treatable with antibiotics or warm compresses.