Quite often tumors in that location will show up during an eye exam if a visual field screening is done. That's a standard part of my eye exam procedure on all patients 18 and over. Most tell me they "never had that test before".
I went in last year for a comprehensive eye exam when I noticed my vision getting worse. I think I can safely rule out that as a possibilty for me at this point in time. Good information for future visits though.