Clear, watery fluid which fills the front chamber of the eye between the cornea and iris/lens. Important to maintain shape and pressure of the eyeball.

A cloudy lens, which causes blurred vision

Ciliary Body
Part of the eye which produces aqueous

‘Cling-film’-like covering of the sclera.

Clear window at the front of the eye. Allows light through and bends (‘refracts’) the light rays

Central part of the macula. Most sensitive part of the retina for detailed vision.

Intraocular Pressure
Pressure within the eye


Coloured part of the eye, which gets smaller in bright light and larger in dim light to control the size of the pupil

Transparent structure shaped like the lens of a camera, which bends (‘refracts’) light rays as they pass through the eye to focus them on the retina

Central area of the retina responsible for good clarity of vision, and damaged in macula degeneration

Ocular Hypertension
Ocular hypertension is raised intraocular pressure with no signs of damage to the optic disc.

Optic Disc
The optic disc is the end of the optic nerve, which is visible to the examiner. A normal looking optic disc is different from one damaged by glaucoma.

Optic Nerve
The optic nerve leaves the eye at the optic disc, and transfers all the visual information to the brain.

The white, outer, protective layer of the eye (underneath the conjunctiva)

Trabecular Meshwork
The part of the eye through which aqueous exits the eye.

Light-sensitive layer of cells which line the back wall of the eye

Visual field
The panoramic view of your surroundings. It becomes constricted in glaucoma.

Clear gel which fills the space between the lens and the retina