Glossary
Perimetry
This test examines the condition of the visual field. For this examination you will be asked to sit in front of a machine with an illuminated bowl and to put your chin on a rest. During the test, you are asked to keep your eye (one eye is tested at a time) on a point in the middle of the bowl while spots of light flash in different parts of the bowl. Each time you see a flash, you are asked to press a button. You are not expected to see all the flashed as some are very dim and many of the points will flash more than once in order to measure how sensitive you are to light from that spot. The test usually lasts about 10 minutes for each eye.
This test tells the doctor a lot about how effective the treatment is being and will help in the decision as to whether your current treatment is sufficient to preserve your sight.
The two pictures below show a normal visual field and one from a patient with glaucoma.
Top
