Is my double vision due to old age or to my Guillian-Barre?

Both Guillian-Barre syndrome (when the body attacks its own nerves, which can lead to paralysis) and aging can cause double vision. Weakness, even paralysis, is not uncommon with certain cases of Guillian-Barre, which can affect all of the muscles in the body. Aging affects muscles too, but not a lot of older people experience double vision. Since this is a somewhat complicated case, I urge you to seek a consultation or second opinion from an ophthalmologist or a neuro-ophthalmologist (an expert in neurology and ophthalmology).