Faster than the Speed of Sight

Researchers at Trinity College Dublin in Ireland recently studied people’s flicker fusion threshold, or “speed of sight,” by having people view a light flickering at various frequencies. The study found that not everyone has the same threshold. Those with higher thresholds could see that the light was flickering when the frequency was quicker. Those with lower thresholds saw a steadily shining light when the flicker frequency was too fast. Speed of sight might explain why some people are more skilled at certain sports, like baseball.

Animals also have a highly varied flicker fusion threshold, often much greater than humans. Whereas this study reported the highest flicker fusion threshold for humans is around 60 hertz, the peregrine falcon (fastest creature on earth) clocks in at about 130 hertz! For animals who hunt quick prey, a higher threshold helps them track what they’re chasing.

Scientists aren’t sure what causes people and animals to have various speeds of sight. Of course before the fall, creatures wouldn’t have used their speedy sight to hunt other creatures. But perhaps our different flicker fusion thresholds are just another example of how God designed his creatures in unique and complex ways to thrive in our fallen world.

This article is from Answers magazine, July–September, 2024, p. 19.