I had an field eye exam earlier and it wasnt good. i might have to get a lumbar puncture. he didnt go into he also said i have pseudotumor cerebri. he didnt go into specifics, but what kind of issues will the spinal tap find?

Appears that there is a concern for increased intracranial pressure, and the spinal tap will measure pressure levels plus additional studies to determine potential etiology. A series of blood tests might reveal causation. If pressure is elevated, it needs control to protect your vision. Since this is very complex, schedule a thorough conference with your doctor, and obtain your medical reports.