Is there a relationship between wandering eye and low iq?

No. Lazy eye (amblyopia) is not necessarily a sign of low iq. However, some persons with congenital syndromes suffer from various forms of strabismus which can lead to lazy eye (amblyopia). Evaluation by an ophthalmologist is recommended.
Low IQ. The only relationship could be inattentiveness associated with a refractive error, and if this is corrected it should make a difference.