Field of vision?

• Treatment of defects of binocular vision (such as strabismus and amblyopia) by nonsurgical measures (especially by exercises to strengthen the eye muscles)

Wikipedia Word definitions in Wikipedia
Orthoptics is a profession allied to medicine whose primary emphasis is the diagnosis and non-surgical management of strabismus (wandering eye), amblyopia (lazy eye) and eye movement disorders. The word orthoptics comes from the Greek words ὀρθός orthos ...

Wiktionary Word definitions in Wiktionary
n. The study and treatment of muscular irregularity of the eye

WordNet Word definitions in WordNet
n. treatment of defects of binocular vision (such as strabismus and amblyopia) by nonsurgical measures (especially by exercises to strengthen the eye muscles)