"We can only generate smooth following eye movements if we have a moving target to lock on," Tadin explained. "We had one synesthete that had perfectly smooth eye movements when following her hand in total darkness. For her, we really thought we made a mistake and left the lights on."
This doesn't mean that humans are preprogrammed to see in the dark.
It's learned, Tadin said, and likely only applies to our own body movement.
Tadin and his colleagues hope this research can one day be used to improve hand-eye coordination. They are currently working on this idea with a group of older adults, a population that often experiences hand-eye coordination difficulties.