cross-eyed

This is when the eyes turn inwards toward the nose. In medical circles, we call this esotropia.  This alignment problem can be congenital or arise in adulthood from a cranial nerve palsy or a stroke.  In childhood, crossed eyes are usually corrected with strabismus surgery.  The goal is to straighten the eyes for primary vision (when looking straight ahead and reading) to help with stereoscopic vision and avoid the formation of amblyopia. Prism glasses can also help alleviate double vision.