1 Touch Response: The keys on a digital piano or keyboard can be weighted (similar to those of a traditional piano), touch sensitive (unweighted but still sound loud when struck hard), or neither.
In very rare instances, eyelid twitching can indicate a more serious condition, like the beginning stages of multiple sclerosis or a lesion on the brain stem. Those conditions typically begin with a host of symptoms, and in this circumstance the eyelid twitch soon moves to the facial muscles, as well.
Tiredness: A lack of sleep, whether because of stress or some other reason, can trigger a twitching eyelid. Catching up on your sleep can help. Eye strain: Vision-related stress can occur if, for instance, you need glasses or a change of glasses.