A chalazion is a small, slow-growing lump or cyst that develops within the eyelid. They are not usually painful and rarely last longer than a few weeks.

A chalazion can develop when a meibomian gland at the edge of an eyelid becomes blocked or inflamed. These glands produce oil that lubricates the surface of the eye.

In this article, we look at the symptoms of a chalazion and the differences between a chalazion and a stye. We also describe causes, home treatment, when to see a doctor, surgery, and prevention.

Symptoms

In the early stages, a chalazion appears as a small, red or otherwise inflamed area of the eyelid.

Within a few days, this inflammation can develop into a painless and slow-growing lump.

A chalazion can appear on the upper or lower eyelid, but they are more common on the upper lid.

Although chalazia are generally painless, they can cause the eye to become watery and mildly irritated. A particularly large chalazion may press on the eyeball, which can lead to blurry vision.

Chalazion vs. stye

People sometimes confuse a chalazion with a stye due to the similarities in appearance. A stye is also a small lump that can develop in the eye area.

Although people often use the two terms interchangeably, they refer to different types of lesion.

A chalazion results from a blocked oil gland, whereas a stye indicates an infected oil gland or hair follicle. However, a chalazion can sometimes develop into a stye.

There are two types of stye:

  • External hordeolum: These occur at the base of the eyelash and usually result from an infection in the hair follicle.
  • Internal hordeolum: These develop inside the eyelid and tend to result from an infection in an oil gland.

The most noticeable difference between a chalazion and a stye is that a chalazion tends to be painless. A stye is usually very painful and may cause the eye to feel sore and scratchy.

 

Other symptoms of a stye can include:

  • swelling of the eyelid
  • a small pimple, which may contain pus
  • crustiness along the edge of the eyelid
  • sensitivity to light
  • a watery eye

Most styes increase in size for around 3 days before the pus begins to drain. They usually take around 1 week to heal.

Causes and risk factors

A chalazion typically occurs in a person with an underlying inflammatory condition that affects the eyes or skin. Some of these conditions include:

  • chronic blepharitis
  • acne rosacea
  • seborrheic dermatitis

Less commonly, chalazia develop due to viral conjunctivitis, which is a type of eye infection.

Individuals who have had a stye or chalazion have an increased risk of developing chalazia in the future.

Other risk factors for a chalazion include:

  • viral infections
  • tuberculosis
  • skin cancer
  • diabetes