Esophoria is characterised by inward deviation of the eye usually due to extra-ocular muscle imbalance. Causes include: Unlike esotropia, fusion is possible and therefore diplopia is uncommon. ... Found on http://en.wikipedia.org/wiki/Esophoria
(es″o-fo´re-ә) heterophoria in which there is deviation of the visual axis of one eye toward that of the other eye in the absence of visual fusional stimuli. Found on http://www.encyclo.co.uk/local/21001