Rheumatoid arthritis (RA) is autoimmune disorder when immune system attack on the joints, lungs, eyes and skin. RA is painful and disabling condition. Your balance problems can be due RA because it causes peripheral neuropathy. Tunnel vision can also be due to RA because it affect eyes.
Long term use of methotrexate which is a cytotoxic drug can also cause blurred vision, dizziness and Loss of memory. So, your problems are directly related with Methotrexate use.
Long term use of methotrexate which is a cytotoxic drug can also cause blurred vision, dizziness and Loss of memory. So, your problems are directly related with Methotrexate use.