Mostly, Glaucoma is associated with Ocular Hypertension, with in turn can lead to a loss of peripheral vision, which is measured at an Opticians or Clinic using the Visual Field Test, where dots of light are displayed around a board at random and you have to say how many of those dots you see.
So a raised Intra- Ocular Pressure and a diminished visual field are some symptoms which you can find with glaucoma, but does not automatically mean that you have glaucoma.
Attending the nurse-led glaucoma clinic should clarify things much more