3 weeks post partum flair up of severe chronic migraine . experiencing fleeting burning pains in both arms and legs and face along with double vision . double vision been ruled as a refractive error non neurological . what could burning pain be ?

Obtain a referral to a neurologist to perform a thorough exam and testing, as "double vison" with "severe headache", although possibly a "refractive error", with new onset of symptoms, other causes need to be ruled out .

A chronic refractive error such as irregular astigmatism would cause persistent, not episodic, diplopia if uncorrected. The neurologist would address migraine and the other symptoms and "episodic diplopia" such as can occur in multiple sclerosis.