Ever try killing a fly, feel like you just aren’t fast enough, well, you aren’t…at least most of us aren’t
Actually, from the fly’s perspective, you quite literally are moving in slow motion, because every species experiences time differently. The reason? Differences in sight.
All animals, including humans, see the world in what’s essentially a seamless movie. What’s really happening, however, is that the brain is taking individual images sent from the eye at a fixed rate per second in distinct flashes and piecing them together.
The rate at which this occurs is called “flicker-fusion frequency,” which is measured by determining how rapidly a light needs to be switched on and off before it appears to an animal as a continuous stream. Scientists measure this in insects by hooking up tiny glass electrodes to the photoreceptors of its eyes and flashing light at increasingly fast speeds, all while a computer graphs the signals sent from the photoreceptors.
It turns out this rate is different for every animal. The general rule is: the smaller the species, the quicker the vision.
Humans see about 60 flashes per second while flies see about 250 – a full four times faster than humans.
In fact, the majority of flying animals, including vertebrates, have faster vision than humans – possibly because it’s mortally important that they’re to quickly react and dodge obstacles.