Doors of perception. How to expand the visible spectrum of human vision
However, such an experience only seems safe if it is short-term. In the medium term, a person’s night vision improves significantly, but daytime vision drops. If you follow a diet on vitamin A2 for about a year, then it is possible irreversible pathological changes in the immune system. However, when this biohackers were stopped such little things.
Nanoadditives and eye microsurgery
Apparently, it is much more convenient to expand the spectrum of vision with the help of nanotechnologies than with the help of biotechnologies. In 2019, a team from the University of Science and Technology of China, led by Xu and Jin Bao, and Gan Han from the Massachusetts Institute of Technology School of Medicine attached to retinal cells in experimental mice. Han suggested that the retinal photoreceptor simply did not have time to catch the infrared wave; it is so long that the photoreceptor has time to “throw off”.
But if terbium or ytterbium nanoparticles are attached to the photoreceptors, then the particle acts as a light transducer. In the experiments of Chinese scientists, they managed to “show” mice infrared light with a wavelength of 980 nm – it was converted into waves with a wavelength of 535 nm, that is, it seemed greenish. Mice definitely reacted to infrared light – in particular, their pupils constricted.
Converting ultraviolet to visible light is somewhat easier, since there are fluorescent molecules that absorb radiation in the near ultraviolet, and emit already in the visible spectrum – for example, they give green light. Many laser dyes (Stilbene-420) can be used for this purpose, as well as well-studied proteins, in particular, green fluorescent protein (GFP). These substances appear to us to be fluorescent, as they scatter (lengthening the wavelength) near ultraviolet. In 2020, a joint US-China study, according to which laser dyes can be applied to light-protective glasses that block long-wave light, and transmit short-wave and ultraviolet light. Fluorescent proteins, in turn, are so harmless that they can be applied to the retina (microdoses of laser dyes can also be injected into the eye mixed with egg white or bovine serum albumin). Theoretically, it would be possible to implant a combined light filter in a person, which would allow simultaneous perception of infrared, visible and ultraviolet light.
Currently, there are prototype glasses developed at the University of Texas that allow you to see such a picture. However, they only work if the light is very strong and don’t filter visual noise well.
Monet and crystal
Apparently within the human variability there are individuals, capturing the nearest ultraviolet at the edge of vision. It appears to a person as a pale purple hue. However, to expand a person’s spectrum of vision in the ultraviolet, it is enough to remove the lens. One of the most important functions of the lens is to block ultraviolet light. At aphakia (congenital or acquired absence of the lens), visual acuity is greatly reduced due to the fact that the accommodation of the eye does not work, but the visible spectrum expands measurably.
Perhaps the most striking experience of this kind was experienced in old age by Claude Monet (1840-1926). The vision of the great artist began to fall in 1905 – he began to develop cataracts.
Cataracts are caused by the accumulation of proteins on the lens. The lens becomes cloudy and yellowish, part of the light ceases to fall into it, and part is scattered. In old age, cataract is a common senile ailment, but Claude Monet caught the disease earlier than usual, perhaps due to a long and active work with lead paints.
Apparently, until the mid-1910s, Monet desperately ignored the problem. With cataracts, vision is reduced due to “glare”, so the artist tried to wear a hat with a brim and work at dusk, when natural light was at its softest.
From 1912 to 1918, Monet’s vision dropped from -1 to -1.5, and by 1922 only -2.5 remained, that is, he was practically blind. Therefore, in 1923, he decided on an operation to remove a cataract.
The doctor operated on only one eye (probably the right one) – in case the eye went completely blind as a result, the old man could see something with the other eye. However, the operation helped, and Monet even returned to painting.
And this is the picture “Water lilies. Clouds, completed by Monet in 1926. At the end of his life, Monet tried to correct previously begun paintings, seriously shifting their spectrum to pale purple. In particular, he was embarrassed by flowers and their shades. It is possible that he saw the flowers “bee-like”, so he tried to convey the newly discovered shades. Color perception without a lens definitely deserves more careful study and clinical research.
Conclusion
The expansion of the visible spectrum is obviously associated with its differentiation into the visible, infrared and ultraviolet segments. In addition to natural night vision, such modifications would quite allow a person to see text readable in the ultraviolet range, or to consider patterns or captchas that are not visible to the naked eye. Perhaps all these improvements in vision will require combining the optical eye with the faceted one, but I prefer to put these questions in the comments.
