Apparently the human retina can detect some UV wavelengths, but the UV light is normally blocked by the lens and does not reach the retina.
Some patients who have had replacement artificial lenses develop the ability to see some portion of the UV spectrum. My mum now has this - she had lens replacement last year and following that she mentioned that a lot of things appeared more purple in some circumstances - my brother did some research and found out about the UV detection.
Some patients who have had replacement artificial lenses develop the ability to see some portion of the UV spectrum. My mum now has this - she had lens replacement last year and following that she mentioned that a lot of things appeared more purple in some circumstances - my brother did some research and found out about the UV detection.
Wikipedia has some info: http://en.wikipedia.org/wiki/Aphakia