A liquid crystal device, and a method and an apparatus for driving the same in which the refractive index of the liquid crystal device is adjusted using a simple driving method and apparatus, which is advantageous in that the cost is reduced, are provided. A liquid crystal device (10) includes a first transparent substrate (1002) and a second transparent substrate (1004) that face each other, a liquid crystal (1014) filled between the first and second transparent substrates (1002, 1004), a first transparent electrode (1006) formed on a surface of the first transparent substrate (1002) that faces the second transparent substrate (1004), and a second transparent electrode (1008) formed on a surface of the second transparent substrate (1004) that faces the first transparent substrate (1002). First and second driving signals (S1, S2) of square waves are applied to the first and second transparent electrodes (1002, 1004) with a time interval t (sec) therebetween. Thus, the potential difference between the first and second driving signals (S1, S2) is applied to the liquid crystal (1014).