A stye appears as a bump on the edge of the eyelid. Similar to a pimple, it is red, swollen, inflamed and tender to the touch. It contains pus and will eventually come to a head, drain and heal if left untreated. A stye is a blocked oil gland and it's possible to have more than one at the same time. There are several causes and different types of eye bumps.
Stye
The University of Maryland Medical Center states that a stye is caused by skin bacteria entering the oil glands that lubricate the eye. It involves a small area of the lid but can cause light sensitivity, excessive tearing and redness of the entire eyelid. A small yellow dot will appear in the center of the bump, drain and heal in about a week. Applying warm compresses for 10 to 15 minutes four times a day will assist in the healing. Antibiotic ointment will help rid the eyelid of bacteria. If it becomes too large, a physician may need to lance and drain it. Never squeeze a stye; allow drainage to occur on its own.
Blepharitis
Similar in nature to a stye, blepharitis is the inflammation of the base of an eyelash from excessive bacteria. The eyelash follicles become plugged and blocked and an infection occurs. The National Institute of Health claims that seborrheic dermatitis, a skin condition that causes the flaking of the skin, may also be a factor. Symptoms are similar to that of a stye. Gentle cleansing of the eye will help remove build-up of oils. Your physician may prescribe antibiotic ointment to help control bacteria on the lid.
Chalazion
There are about 100 Meibomian glands in the eyelid, according to the National Institute of of Health. They are located near the eyelashes and are responsible for lubricating the eye. When a duct becomes blocked a chalzion, or small bump, occurs. Swelling and tenderness along with redness are symptoms. Warm, intermittent compresses applied to the eye will help drain the duct. A chalzion will disappear in about four weeks, but if it continues to grow, seek medical attention.


