Commentary for Berakhot 105:1

אי נימא לא שבת מחמת מלאכה אפילו ממלאכה דהתירא והתניא אור של חיה ושל חולה מברכין עליו

If we would say that it has not rested because of work [which has been done on the Sabbath by its illumination], even if it be work which is permitted, there is a teaching : We may say the benediction over the light used [on the Sabbath] by a woman in confinement or an invalid !

Abraham Cohen Footnotes to the English Translation of Masechet Berakhot