Glaucoma is a condition that damages your eye's optic nerve. It gets worse over time. It's often linked to a buildup of pressure inside your eye. Glaucoma tends to run in families. You usually don’t get it until later in life.
The increased pressure in your eye, called intraocular pressure, can damage your optic nerve, which sends images to your brain. If the damage worsens, glaucoma can cause permanent vision loss or even total blindness within a few years.
The fluid inside your eye, called aqueous humor, usually flows out of your eye through a mesh-like channel. If this channel gets blocked, the liquid builds up. Sometimes, experts don’t know what causes this blockage. But it can be inherited, meaning it’s passed from parents to children.
Less-common causes of glaucoma include a blunt or chemical injury to your eye, severe eye infection, blocked blood vessels inside your eye, and inflammatory conditions. It’s rare, but eye surgery to correct another condition can sometimes bring it on. It usually affects both eyes, but it may be worse in one than the other.