'light-related' originates from the English word 'light' combined with the suffix '-related', where 'light' meant 'the natural agent that stimulates sight and makes things visible' and '-related' indicates a connection or association.

'light' changed from the Old English word 'leoht' and eventually became the modern English word 'light'.

Initially, 'light' meant 'brightness or illumination', and this meaning has largely remained the same in modern usage.