PROBLEM TO BE SOLVED: To provide a visual acuity testing device and visual acuity testing system capable of easily testing the practical visual acuity of a subject. SOLUTION: This visual acuity testing device comprises a target presentation means for successively presenting visual acuity testing targets to the subject, an input means for inputting the answer of the subject, and a means for whether the inputted answer is right or not to test the visual acuity of the subject. This device further comprises a mode switching means for switching a general visual acuity testing mode for measuring the general visual acuity of the eye to be tested to a practical visual acuity testing mode for measuring the visual acuity change when continuing the eyelid opening of the eye to be tested a target presentation program for presenting a target of a visual acuity value corresponding to the general visual acuity value of the eye first to start a test, and presenting a target of a lower visual acuity value when the answer of the subject does not satisfy a prescribed standard and a measurement result storing means for storing the measurement result in the practical visual acuity testing mode together with time axis.
