Glossary of Terms:
Angle Closure Glaucoma: A type of glaucoma caused by a sudden and severe rise in eye pressure. This occurs when the pupil enlarges too much or too quickly and the outer edge of the iris blocks the eye�s drainage canals. This can be either acute or chronic.

Pupil: The opening that monitors how much light enters the eye. (The black part of the eye)

Iris: The colored part of the eye that can expand or contract to allow just the right amount of light into the eye.

Central vision: What you see when you look straight ahead.

Peripheral vision: The top, sides and bottom areas of vision. These are usually the first areas of vision affected by glaucoma.

Congenital glaucoma: A rare form of glaucoma that occurs in babies and young children. This condition can be inherited. It is usually the result of incorrect or incomplete development of the eye's drainage canals during the prenatal period.

Conjunctiva: A thin, clear membrane that lines the inner surface of the eyelids and the outer surface of the eyeball, except for the cornea.

Cornea: The clear part of the eye located in front of the iris. Part of the eye�s protective covering.

Drainage canals: Small openings around the outer edge of the iris. These canals provide the final pathway for fluid to leave the inside of the eye. Sometimes referred to as the trabecular meshwork or Schlemm�s canal.

Intraocular pressure: The inner pressure of the eye. Normal intraocular pressure usually ranges from 12-22mm of Mercury, although people with relatively low pressures can still have glaucoma (see normal tension glaucoma).

Lens: Located behind the iris, this helps light focus onto the retina.

Normal tension glaucoma: Also called low tension glaucoma; A form of glaucoma in which the intraocular pressure stays within the normal range (12-22) but damage still occurs to the optic nerve and visual fields.

Optic nerve: The nerve in the back of the eye that carries visual images to the brain.

Open angle glaucoma: The most common form of glaucoma, this form usually develops very slowly as the eye�s drainage canals gradually become clogged. There are no early warning signs for open angle glaucoma which is why it is often called the �sneak thief of sight�.

Perimetry: Also known as the visual field test. A test that produces a map of the complete field of vision to check whether there is damage to any area of vision:

Retina: The part of the eye that carries light and images to the brain through the optic nerve.

Sclera: The tough, white protective outer covering of the eye.

Secondary open angle glaucoma: A form of glaucoma that can occur as the result of an eye injury, inflammation or tumor.

Pigmentary glaucoma:

Tonometry: The use of a device to measure the pressure in the eye.

BACK TO TOP >>>