photoptometer

photoptometer

 [fo″top-tom´ĕ-ter]
an instrument for measuring visual acuity by determining the smallest amount of light that will render an object just visible.

photoptometer

/pho·top·tom·e·ter/ (fo″top-tom´ĕ-ter) an instrument for measuring visual acuity by determining the smallest amount of light that will render an object just visible.

photoptometer

(fō-tŏp-tŏm′ĕ-tĕr) [″ + opsis, vision, + metron, measure]
A device for determining the smallest amount of light that will make an object visible.