- Education and Science»
- Life Sciences
What is the difference between a chalazion and a stye?
A chalazion is a condition that affects the eyelids. It is a firm lump that forms in the upper or lower eyelid.
A chalazion starts to develop when the opening of an oil gland on the eyelid is blocked by small particles such as grains of dust, dirt or microscopic pollen.
A chalazion is not an infection or growth; it is a swelling that can be prominently seen on the eyelid. It starts as a small lump but can grow in size.
A chalazion is also known as the meimobian cyst, tarsal cyst or conjunctival granuloma. A chalazion is a Greek word that means a small pimple. It is usually harmless and does not affect eye vision.
How does a chalazion form?
The upper and lower eyelids have oil glands present along the margins just behind the eyelashes. There are about 30-40 oil glands in each of the eyelids. These oil glands produce oil that is released into the eyes in order to keep the eyes moist and lubricated.
The opening of an oil gland can get blocked by microscopic particles and prevent the oil from oozing out into the eyes. When this happens, the oil gland starts to swell in size.
As more and more of oil gets collected in the oil gland, the pressure inside increases and this can cause a rupture in the walls of the oil gland.
When the walls of the oil gland rupture, the oil flows back into the eyelid and starts to collect in a small sac. When the pore continues to be blocked, more and more oil gets collected and the sac increases in size causing a swelling or a bump on the eyelid. This swelling is called a chalazion.
The chalazion is painless and is firm to touch. When a chalazion forms, it looks like a small, tender red swelling on the eyelid. As it grows, it becomes a firm lump that may grow to the size of a pea.
People who are prone to the following conditions are more likely to develop a chalazion -
- viral infection
- chronic inflammation of the eyelids
- chronic inflammation of the eyelashes
What is a stye?
A stye is a lump that can form on the inside or the outside of the eyelid. It is a soft swelling that is filled with pus and is the result of an infection by the Staphylococcus aureus bacteria.
There are two types of styes -
- external stye
- internal stye
A stye that forms on the outer margin of the eyelid is called an external stye. The external stye starts as a small spot at the base of an eyelash. During the stages of infection, it can become red and painful before it finally bursts. The external stye usually breaks and heals by itself.
A stye that forms on the inner margin of the eyelid is known as an internal stye. The internal stye is also painful and appears red and inflamed. When an internal stye bursts open, it may leave a sac filled with fluid, a cyst or a nodule that can remain for a long time and has to be cut open and drained.
A chalazion and a stye are not one and the same. A chalazion may occur as an after effect of a stye.
How does a chalazion differ from a stye?
A chalazion is caused when the opening of oil glands on the eyelids get blocked
A stye is caused when an oil gland present at the base of an eyelash is infected by the Staphyloccocus aureus bacteria
Does not cause pain
Causes mild to extreme pain
Chalazion is found away from the margin of the eyelid
Stye is found on the margin of the eyelid
What to do when you have a chalazion
A chalazion may not go away on its own. This condition may require a visit to the eye doctor. When you have a chalazion, the doctor will recommend warm compresses and prescribe antibiotic eye drops to prevent infection of the chalazion.
If the chalazion persists or grows in size it can be removed surgically by your eye doctor under local anesthesia. It is an outpatient procedure. There are chances of a chalazion recurring again.
Removing a chalazion by surgical procedure does not cause any distortion in eye vision nor does it affect the functioning of the eyelids or tear glands.