A gently lobbed baseball is easy to see. The same ball, however, can seem to vanish from the hand of a skilled pitcher, whizzing invisibly into the catcher’s mitt.

Given enough acceleration, moving objects become too fast to see. Yet this visual speed limit isn’t universal – some people are apparently better at seeing in high-speed.

According to a new study, the secret may lie in subtle eye movements known as saccades. These rapid motions of the eyes shift our focus between various points of interest, and are regarded as the most frequent movement the human body makes. By some calculations they occur two to three times every second, adding up to around 10,000 times every waking hour.