To compare horizontal strabismus deviation as assessed from photographs with that in the strabismus clinic using the prism bar.

Purpose: To compare the deviation in cases of horizontal strabismus as assessed from photographs with the measurements as obtained in the strabismus clinic.

Methods: After obtaining informed consent, we recruited subjects with manifest horizontal strabismus. We took a frontal flash photograph from a distance of 50 cm using smart-phone-based cameras with the flash light vertically aligned with the lens.