esotropia. horizontal strabismus before and after surgery. eye misalignment, cross-eyed condition. human eyes healthy

esotropia strabismus eye squint inward misalignment crossed horizontal amblyopia movement vision double deviation ophthalmology eyeball human disorder optometric iris pupil type anatomy muscle extraocular health convergent heterotropia condition dysfunction farsightedness diverge misaligned diagnosis infographic symptom tropia drift position diplopia binocular gaze comparison patient medical therapy surgery before after