How often should you have a visual field test when you have glaucoma?

Visual field test: In stable glaucoma, normally done once a year to verify that no change for the worse is occurring. If so, treatment will be intensified. If your glaucoma is unstable, or a change in the optic nerve is noted, a visual field is done at that time even if already done that year. Visual fields are measured besides the optic nerve cup/disc ratio, intraocular pressure, and nerve fiber layer.

Depends: Depends on the index of suspicion that you may have glaucoma, on the severity of the glaucoma if you have it, and/or how well-controlled your eye pressure is. Ask your glaucoma doctor to clarify this for you.