I was reading something yesterday about alarm clocks which wake you up by means of a light which gradually gets brighter - imitating dawn. The article I read - can't find it now so I can't add a link to it - seemed to be saying they are a new invention. The sophisticated versions which are sold today with the means to play music or tune in to a radio station are new, but ones like mine have been around about 15 years I think.
I've certainly had mine about 10 years. It isn't very pretty but it is absolutely brilliant. The back up on mine is a conventional alarm which will wake you up if the light doesn't but 99 times out of 100 the light wakes me up before the alarm. I don't wake up startled with my heart pounding like I did with a conventional alarm clock and when it eventually goes wrong I shall buy a new one. I shall probably have to replace it soon because it takes 60watt screw in candle bulbs. You can also use it in reverse to go to sleep.
What amazed me was the comments - from people who plainly hadn't tried it - were that it was just a gimmick and couldn't possibly work and only the gullible will buy them. 10 years use suggests otherwise. I used to hate the fact I had to rely on the alarm on my phone or a phone call from hotel reception when I was working away from home. I do still use the alarm - even though I am retired - I find keeping to some sort of a routine means I sleep much better. Though I do get up later - about 8.00am - than I used to.