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I was just reading the Wikipedia article on Tetrachromacy and saw this interesting fact. "Humans cannot see ultraviolet light directly because the lens of the
by vanattab 10y ago
I was just reading the Wikipedia article on Tetrachromacy and saw this interesting fact.
"Humans cannot see ultraviolet light directly because the lens of the eye blocks most light in the wavelength range of 300–400 nm; shorter wavelengths are blocked by the cornea.[27] The photoreceptor cells of the retina are sensitive to near ultraviolet light and people lacking a lens (a condition known as aphakia) see near ultraviolet light (down to 300 nm) as whitish blue, or for some wavelengths, whitish violet, probably because all three types of cones are roughly equally sensitive to ultraviolet light, but blue cones a bit more."
https://en.wikipedia.org/wiki/Tetrachromacy https://en.wikipedia.org/wiki/Tetrachromacy
- hatsunearu 10y agoHmm, I see those "blacklight" CFL ultraviolet lamps as violet-white. I see the sameish color on ultraviolet lasers. Am I the only one who sees it that way? Can anyone describe how they perceive those lamps? Communicating color is extremely difficult!
- jhayward 10y ago> Communicating color is extremely difficult! Odd personal anecdote: In first grade art class the teacher held up a piece of art paper and said "This is red". Being the curious student I was, I raised my hand and asked "how do you know?" I was looking for something that would answer both "how do you know I perceive red the same way you do" and also "what defines it to be red". Something about wavelengths and color spectrum etc. would have been a great answer. I was sent to the principal's office as a troublemaker. Never did like art class after that.