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.
A twitching eye can be one sign of stress, especially when it is related to vision problems such as eye strain (see below). Reducing the cause of the stress can help make the twitching stop. 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. Your eyes may be working too hard, triggering eyelid twitching. Computer eye strain from overuse of computers, tablets and smartphones is also a very common cause of vision-related stress.