Analysis of information sources in references of the Wikipedia article "Fasciculation" in English language version.
Tics must also be distinguished from fasciculations. Small contractions of the upper or lower eyelid, for example, are not tics, because they do not involve an entire muscle. They are contractions of some bundles of muscle fibres, which can be felt but just seen. These contractions of the eyelids also differ from tics in that they are not suppressible, are strictly involuntary and tend to fade after a day or two.
Tics must also be distinguished from fasciculations. Small contractions of the upper or lower eyelid, for example, are not tics, because they do not involve an entire muscle. They are contractions of some bundles of muscle fibres, which can be felt but just seen. These contractions of the eyelids also differ from tics in that they are not suppressible, are strictly involuntary and tend to fade after a day or two.