An Unobvious Cause of Deteriorating Eye Function Identified 0 8

Conversation while performing visually-motor tasks (for example, while driving) creates a cognitive load that can disrupt eye function — this conclusion was reached by scientists from Fujita Health University. The study, published in the journal PLOS ONE, showed that even a simple conversation slows down key stages of eye movements necessary for timely perception of the surrounding environment, including while driving.

In an experiment involving 30 healthy volunteers, researchers compared eye movements under three conditions: during conversation, while passively listening to text, and without additional load. It turned out that it was the conversation — and not just auditory perception — that increased the reaction time of the gaze, slowed its movement toward the target, and worsened fixation on the object. All these delays occurred at early stages of visual processing.

According to the authors, although each individual delay is small, in real-world conditions they can accumulate and lead to later detection of hazards — pedestrians, obstacles, or signals on the road. This is particularly important since about 90 percent of the information necessary for safe driving is obtained through vision.

The study confirms that conversation, including hands-free communication, can subtly impair visually-motor mechanisms even before the stages of recognition and decision-making. The authors emphasize that the cognitive load from conversation may be one of the factors increasing the risk of errors and accidents in complex situations.