The usual cause of this is pressure on the iris - from the part of the aqueous humour that is behind the iris.
As shown in the diagram of the eye, most of the aqueous humour is between the iris and the cornea. Pressure can build-up in the part of the aqueous humour located behind the iris when it cannot pass through the pupil to the anterior chamber of the eye. This situation may be referred to as "pupil-block glaucoma".
More about Ophthalmology:
This section includes short definitions
of many diseases, disorders, and conditions of the eyes and visual system.
For definitions of other terms in this category, choose from the list to the left (but note that this is not a complete/exhaustive list).
Other related pages include
- A diagram of the eye
- Definitions and descriptions of the parts of the eye
- A concise description of the human retina
- Definitions of parts of the retina
- Clinical and surgical procedures re. eyes and human visual system
For further information see also our pages of books about ophthalmology.