Actually, I think if some one lack of calcium will cause the eyes to twitch. The too less or too much calcium contains than average will cause diseases both. The too much calcium will induce urinary stone, and lack of it will lead to twitch especially hands and legs' twitch. The process of twitch will last several seconds to dozens of seconds, 1 to 20 times one day. Calcium will control the movement of nerves and muscles, if you lack of it, the nerves will malfunction, the twitch will happen. However, the twitch will not only caused by lack of calcium, it may caused by eyes fatigue or high blood pressure even heart disease and diabetes. These diseases are easily happen in the old people's body. Which reason cause your eyes twitch, please go to doctor for safeguard of your health.