What Is A Visual Field?
Of all the tests the ophthalmologist has at his disposal, the visual field (VF) test is probably the most often disliked and misunderstood by the patient.
However, because of its versatility, it can be used to diagnose and monitor several eye disorders. These include glaucoma, detached retina, strokes, brain tumor and others. This versatility makes the VF test one of the most useful tests available to the ophthalmologist.
By far the most common use of the VF is to diagnose and monitor treatment of glaucoma. Glaucoma is characterized by the build-up of fluid in the eye which produces intraocular pressure (IOP) on the optic nerve thereby causing a deterioration of that person's peripheral, or side vision.
When an ophthalmologist suspects that a person's IOP is too high, he will perform a VF to see if this deterioration of peripheral vision has begun. If it has, then the IOP must be lowered to a level where the deterioration ceases, using eye drops, laser treatment, or in extreme cases, surgery.
The only way an ophthalmologist can be sure he has the IOP low enough so as not to cause peripheral vision deterioration is to perform periodic visual fields.