I am 28 and have worn corrective lenses since about 3rd grade. At my last annual check-up my doctor noticed some damage to optic nerve in my left eye. Thought it could be onset of Glaucoma and scheduled Visual Field test. The testing device is called Oculus Easyfield. I passed in my right eye and barely failed in my left eye. Scheduled a follow-up Visual Field test with more or less the same results. Of interest to her though is that the area of my left eye that seemed to be a problem was the top section, slightly to the left. She advised that because it was that area, it didn't seem likely it would be glaucoma. She wants to do one more Visual Field test. I asked her what it would be if I failed in that part of my eye again and it wasn't glaucoma - she said not to worry about it right now. She asked if I noticed if it was blurry in that area when doing the test and I told her that I didn't notice. Also, I was tired and had a little trouble focusing when I took my second test. I am not really worried but feeling a little unsettled about it. What could cause this?