exotropia vs strabismus

exotropia

noun
  • A form of strabismus in which the eyes deviate outwards. 

strabismus

noun
  • A defect of vision in which one eye cannot focus with the other on an object because of imbalance of the eye muscles; a squint. 

How often have the words exotropia and strabismus occurred in a corpus of books? (source: Google Ngram Viewer )