The real reason why our eyes flicker while we sleep

Ever wondered why people’s eyeballs still dart around constantly even when they are asleep? Scientists have finally found the answer by demonstrating how during dreams, our brains and eyes react similarly to how they react to images when we’re awake.

University of California's Dr Itzhak Fried, the study’s lead researcher implanted electrodes deep into the brains of 19 participants, who had drug-resistant epilepsy. The electrodes then recorded the electrical activities of individual neurons in the median temporal lobe for a period of two weeks. This allowed Dr Fried a doorway to attempt understanding the patients’ dreams.

“Brain cells in the medial temporal lobe showed a sudden surge of activity each time after patients moved their eye in REM sleep,” Dr Fried says, according to the Daily Mail. “This electrical pattern closely resembles what happens when we view something new in waking life,” he adds.

To put it in simple words, this means that rapid eye movement captures frames of dream imagery, which means that the same machinery that's responsible for our conscious visual experience also works during sleep. This study was published in Nature Communications to help understand the workings of individual brain cells in the sleeping mind.