Crossword Genius

Light to vital rule alteration (11)

Ross

I believe the answer is:

ultraviolet

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'light' is the definition.
The answer and definition can be both types of natural phenomena as well as being singular nouns.
Perhaps they are linked in a way I don't understand?

'to vital rule alteration' is the wordplay.
'to vital rule' can be anagrammed to 'ULTRAVIOLET'.
But, I'm not sure how this is indicated.

Can you help me to learn more?

(Other definitions for ultraviolet that I've seen before include "Beyond one end of the visible spectrum" , "form of invisible radiation" , "Having shorter than visible wavelength" , "Type of radiation" , "like some rays" .)

I've seen this clue in the Sydney Morning Herald.
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