MODEL RELEASED. Bell's palsy. Face of a man with right-sided Bell's palsy. This is a condition where the facial nerve is affected and one side of the face is paralysed. It can cause nervous tics, which are involuntary movements such as winking or baring of the teeth. The condition may also cause numbness, drooling, altered taste and hearing, and tear discharge from the eyes as seen here. Treatment involves protecting the eye on the affected side, as blinking is often impossible. Normal function may return without treatment, though steroid and antiviral drugs may also be used, as a viral cause is often suspected.