Any science textbook will tell you that humans cannot see infrared light, but researchers have found that under certain conditions our eyes can actually detect the ‘invisible’ light.
Like X-rays and radio waves, infrared light waves are outside the visual spectrum.
Using cells from the retinas of mice and people, and powerful lasers that emit pulses of infrared light, the researchers found that when laser light pulses rapidly, light-sensing cells in the retina sometimes get a double hit of infrared energy.
When that happens, the eye is able to detect light that falls outside the visible spectrum.
“We’re using what we learned in these experiments to try to develop a new tool that would allow physicians to not only examine the eye but also to stimulate specific parts of the retina to determine whether it’s functioning properly,” said senior investigator Vladimir J Kefalov, associate professor of ophthalmology and visual sciences at Washington University.
The study was initiated after scientists reported seeing occasional flashes of green light while working with an infrared laser.