Why do our eyelids twitch?

Volume 10 Number 3 March 10 - April 13 2014

 

Have you ever had one of those annoying eyelid twitches that can last for a couple of days? Andi Horvath explains the condition.

These spasms usually occur in the lower eyelids, and tend to happen when people are stressed, tired or have had too much caffeine. 

Even more annoyingly, if the twitching is large enough, the image in that eye may also jiggle.

Though people feel like they are literally on the blink, thankfully it seems to go away on its own. Voice ponders: are eyelid twitches triggered by some change in the biochemistry of the body, misfiring in the brain, the muscles or the nerves? And why does the eyelid twitch, why not the knee cap or little finger? What’s special about the eyelid nerves or muscles?

Associate Professor Larry Abel from the department of Optometry and Vision Sciences explains.

“One of the muscles that move the eye is called the superior oblique and a twitch is re- ferred to as a mykomia, so unsurprisingly this condition is called a superior oblique myoky- mia,” he says.

“Because this type of eye twitch is tempo- rary and benign – it has no harmful effects – it’s not the subject of much research.”

There seems to be only one retrospective study of 15 patients, done 10 years ago at Johns Hopkins Hospital. They found if these twitches aren’t associated with any other bits of the face starting to twitch as well, that they are indeed benign.

They couldn’t say what the cause was.

The factors were associated with them though are same ones that are part of the folk wisdom concerning the condition – fatigue, stress, caffeine, alcohol, smoking.

Often they will go away on their own. If they don’t, surgery is a possible option, as is botuli- num toxin (Botox) injection.

Other treatments have been suggested, such as Magnesium deficiency, but the science has yet to be done to confirm or deny the claim. While they think they know why the superior oblique twitches (an artery pressing on its nerve), people are left in the dark about eyelid twitches.

So why isn’t there more research on an eye twitch problem that annoys so many people? In an environment where research funding is constrained, it is directed largely towards problems that tend be relatively common and cause severe disability or death.

Associate Professor Abel says one of the conditions he studies – congenital nystagmus – is relatively common and often causes significant visual impairment in individuals with the condi- tion, but it receives negligible research funding worldwide, since the impairment isn’t as severe as that in, say, retinitis pigmentosa, an inher- ited condition that also results in severe vision impairment.

“So this sort of funding triage means that you probably won’t soon be seeing any state-of- the-art imaging studies of lid twitching coming out of the Melbourne Brain Centre’s new 7T MRI scanner,” he says.

“So what can you do in the interim? Try to get more rest, reduce stress, easy up on the coffees. But you already knew that.”

 

https://www.optometry.unimelb.edu.au/