I heard it before from my friends. It is an eye diseases called Bell's Palsy. You'd better go to an ophthalmologist who is a medical doctor. The consequences can be very serious. So, you should take it seriously and get help from eye doctor.
I have seen this before. Although many people say it is ok, you still need to go to see the doctor and have a check. From the aspect of medical science, this symptom is called the Bell's Palsy. It is a complicated symptom. You should take it serious and go to have a check in hospital as soon as possible.