In a surprising discovery, scientists at Washington University have found that humans can see near-infrared light under certain conditions. While it is commonly believed that the human eye is not designed to see infrared light, the researchers found that people can perceive wavelengths up to 1,000 nm when the right conditions are present. The team, led by Dr. Vladimir J. Kefalov, published their findings in the Proceedings of the National Academy of Sciences (PNAS).
The human eye is one of our five senses and is closely connected to the brain. The process of sight is a complex interplay of various components of the eye. The visible light spectrum is believed to range from about 380 to 780 nm. However, the researchers found that people can perceive wavelengths up to 1,000 nm when the right conditions are present. The team used fast-pulsed infrared lasers in their experiments and found that visible light flashes occurred by chance. Further experiments showed that the probability of perceiving the light of the infrared laser increased with shorter light pulses.
According to Dr. Kefalov and his team, the perception of infrared light is likely due to the fact that, in some cases, two photons instead of one hit the retina simultaneously. The energy of two photons with a wavelength of 1,000 nm can then add up, causing the eye to perceive a wavelength of 500 nm. This discovery challenges the commonly held belief that the human eye cannot see infrared light and raises questions about the limits of human perception.
In conclusion, the study by Washington University scientists has shown that humans can see near-infrared light under certain conditions. The discovery challenges the conventional wisdom that the human eye is not designed to see infrared light and raises questions about the limits of human perception. Further research is needed to fully understand the mechanisms behind this phenomenon and its potential applications.
