A chalazion is a red bump on your eyelid.

It is sometimes called an eyelid cyst or a meibomian cyst. It slowly forms when an oil gland (called a meibomian) becomes blocked.

At first, the chalazion may be painful, but after a little time, it usually doesn't hurt.

When you have a chalazion, you will notice the following symptoms:

• Painless bump in your eyelid, usually on the upper lid.
• Mild irritation, causing your eyes to water.
• Blurred vision from larger chalazion that push on the eyeball.