Injections can give you near-infrared vision

Scientists in China and the USA have developed a technique to extend the range of vision by injecting nanoparticles behind the retina (so without any external technology). These particles bind to the photoreceptors in the eye and can convert low energy (near-infrared) photons to a higher energy (green). This has been demonstrated to allow mice to add near-infrared to their range of visible 'colours' with no side-effects.

I first came across this in New Scientist: Mice given ‘night vision’ by injecting nanoparticles into their eyes ... but the full paper is also available online via Cell.com.

One interesting thing about this is that a transfer of energy also occurs in photosynthesis, between types of chlorophyl, and in sensitising film to accept longer-wavelengths.

[Ma et al., Mammalian Near-Infrared Image Vision through Injectable and Self-Powered Retinal Nanoanten- nae, Cell (2019), https://doi.org/10.1016/j.cell.2019.01.038]