There must be some inflammation for your eyes. You may use your eyes too much time everyday in front of the computers or other electric products. You'd better go to see the doctor and have a full check on the eyes. During this time, you should have a good rest for the eyes in case of the tiredness.
As a matter of fact, sometimes I also have the same feeling with you. Before long, I came to know that it was just because I worked too hard and had a lack of sleep. Generally speaking, stress and fatigue could lead to such feelings and the disorder of your eyes is a sign of your health condition which you should pay more attention to. But if things remain the same after taking some measures, just visit a professional doctor.
Did you drinking? As far as i know, Too much alcohol intake could be a factor of shake eyes. Besides, tiredness and eye strain can also cause the eyes shake. If you didn't drink or take drugs and feel tired, you'd better see a doctor and get your eyes checked. You can know what really happen to your eyes only if taking an complete eye check. Hope this can help you.