Here is what one researcher reports about visual perception of 375nm and lower:
"Over the years they've done plenty of vision studies involving ultraviolet, both on normal people and aphakics (people missing a lens in at least one eye). The color varies depending on the intensity. At high intensity it tends to look white or grey, at low intensity like grayish violet. At middle intensities it looks violet down to 395 nm (±5). Below that it trends toward bluish gray, becoming pure gray at 375 nm. Below that it trends towards blue, becoming pure blue at 350 nm. Below that it trends back towards gray.
Down to about 334 nm, the colors are about the same for normals and aphakics. Below that, color fades out faster for normals.
The lowest wavelength at which people still have some visual acuity and color perception is 310 nm. At that wavelength, people can still read an eye chart, but only at a distance of 4 inches. (Normally people can't even focus that close, but at 310 nm they can.)"
Between 310 and 302 nm the opacity of both the lens and cornea increase by several orders of magnitude. At 302 nm people only see a gray blur, and only with 1-hour dark-adapted eyes and if the uv is intense. At 310 nm, on the other hand, eyes don't need to be dark-adapted, the room lights can be kept on.
Starting around age 30-45 the lower limit of vision in the ultraviolet starts to go up, so that the middle-aged can usually see uv only down to about 334-365nm."
"The lens of the eye absorbs ultraviolet light (which is fortunate since UV has a different focal length than white light) .
This means that all the other colors can be focused into a sharp image. but adding UV acts to blur it."
and I'm sad I didn't get more microboost drives too.
