Reaction time refers to the ability to respond quickly to a stimulus. It is important in sports, traffic and even some daily activities, though it is not yet often measured in vision tests. Simple vision-based reaction time is the time taken between a visual stimulus and the corresponding physical action.
In the Ocusweep test for the reaction time, the speed of vision stands for the pace at which the eyes, brain and hands operate together, that relates to the processing speed of the neural system, as well.
In practice, when one sees a stimulus, a signal will travel from the eyes along an optic nerve to be registered in the brain. Subsequently, a message is sent to another part of the brain that controls the muscles. The brain must then send another signal along the nerves to the muscles, telling them to act in line with the instructions.
This is called vision-based reaction time. If the sensory impressions are processed fast, the functionality is efficient, and vice versa.
For instance, sportsmen receive visual stimuli and try and take fast actions accordingly. Skilled sportsmen further reduce their overall reaction time by selecting and combining the most important information (visual, hearing-based and kinaesthetic) they receive and by anticipating other actions and the path of the race/game quickly.
Vision based reaction time is important for one’s performance and safety, and it tends to decline with age. Slow reaction time may be harmful and in the worst case, have serious consequences in suddenly occurring situations, e.g. in traffic. Such being the case, one should keep a greater distance (safety margin) to other cars in order to avoid accidents, no matter how sharp, wide, or clear one’s vision otherwise might be.
Further, reaction time normally increases in poor visibility, i.e. bad weather, low contrast, problems with visual field, etc. that lead to slower responses. Time to respond may also get prolonged even within the same task but under different conditions (e.g. when one gets tired during a long-haul journey at the driving wheel). Also, distraction (e.g. the use of a phone – even in a hands-free mode – while driving) normally results in a prolonged reaction time.
Reaction time can be improved with exercise, especially playing games (e.g. video games, tennis or racquetball) that require quick responses and anticipation. Even stress management and mental exercises (such as yoga) may help one to stay calm and focused in situations where fast reactions are needed.
Vision based reaction time needs to be understood as an integral part of a functional and healthy neuro-visual system and tested periodically (among other aspects affecting functional vision).
Mika Mahlamäki, Business Development Manager, Ocusweep