Date Purchased: 12/1/2015Date Received: 12/4/2015In-Use Date: 12/6/2015Review Type: Standard Amazon PriceThe Need-------------For years I've had pretty bad cases of what was sometimes called "winter blues" but is now recognized to be Seasonal Affect Disorder. It started (or was noticed) when I was a fairly young kid and continues to this day. I've tried many things over the years but recently I had a distant relative come to visit and it turns out she also has dealt with this. She told me that she had been using light therapy for the last 2 years and that it had made a tremendous impact in her mood and energy levels. I've looked in to light therapy many times before but whenever I went looking for a light it always seemed like it was every quack and con-man offering one and never anything that resembled respected medical and scientific information.This time, after talking with her and now feeling that at least in theory the therapy was valid, I was determined to understand more about these lights and what was really behind them. Perhaps this time was also different because I had been dealing with coral and plant grow lights for a couple of years so now had a decent grasp on LUX, color ranges, wavelengths, etc. Whatever the reason, with this knowledge in hand this time it was clearer that when a lamp manufacturer or company was promoting their product with anything under 10k LUX and without specific testing of output, color temp and UV blocking as "light therapy" they were basically preying upon a mostly uninformed marketplace. Products that cost $50-$100 are simply not equivalent to professionally researched, built and tested products no matter how they try to market themselves.The Research-------------------After a good deal of research I decided upon the Carex Day-Light Sky unit. I preferred the non-clinical look of it compared to some of the other Carex models and other brands. As I intended to use this in my home office area, I liked being able to use it for a task-light when not being used for light therapy purposes. It was well reviewed by consumers and was noted in reliable research. It wasn't until I received the box that I became aware that the unit is built like a tank. As per some of the questions asked about the product, anyone thinking of suspending this light above their heads better have a good idea of what they are doing in mounting it due to the potential damage to your wall, light...and skull.I read through the manual and all online information I could find in order to get valid information about the use of the product. Contrary to a lot of the information suggested in the questions above and online in general the unit is intended be used 1) approximately 1 ft from your face 2) the light should be directly in front of you, not off to the side and 3) the light should be shining down from slightly above your eyes. The receptors that are most impacted by this light are along the lower portion of your eye socket so light that is entering your eye from or below horizontal will be less beneficial than if the light is used as the manufacturer suggests. This is why the unit is built as it is, with the light emitting from the panel sitting above your eye height and down at a slight angle towards you.The research behind light therapy shows that the intensity of the light is what has proven to be effective as light therapy, which is why the 10k LUX is so important. If you are receiving light that is less intense it simply does not have the same effect on your body. It should also be noted that light intensity follows the inverse square law. This means that when the the manufacturer suggests that you sit 1 ft from light, thinking that you can sit 2 ft away and still receive half the intensity is incorrect; at 2 ft away you are receiving 25% of the original light intensity. And that again takes you to a level of intensity that is unlikely to have much, if any, of the desired effect for S.A.D.The Effect--------------I started with 20 minutes per day for about the first week just to make sure there were no ill side-effects, especially with the wide variety of medications I am prescribed. As I did not notice anything of issue, I went up to 30 minutes. By this point I believed I was feeling some of the effects but couldn't be sure due to the mood issues from S.A.D. and/or a placebo effect. However by the end of the second week there was absolutely no doubt that the therapy was working. I undertook this therapy in December, usually one of the worst times of year for my condition, and for the first time in a number of years I actually managed to keep some momentum through December and in to this year. It's been about a decade since the last time that happened.In order to make sure that this was not due to something other than the light or that this would be a short-term effect I have waited to write a review. As we entered spring and the time change, I tapered off of the light usage as I was able to get more natural light. Now, 8 months from when I started using it, I can firmly state that this therapy not only helped me through winter but that due to my other health issues there are times I am unable to spend significant time in sunlight and a couple of doses from this light are enough to make a difference. I expect to resume more regular use of the light again as we head in to late fall and the time changes, providing less natural light exposure each day.Lastly, I mentioned that the product is built like a tank. This is a very well built product. No skimping on "lightweight" parts either in the physical build or as far as I can tell in the electronics that control the lighting. I see zero flicker. The lights come on and turn off instantly. There is no sound and only a little heat produced by the light. The arm and adjustments that hold the light have virtually zero play in them. I wish more products were built like this one.I give this product a hearty 5 five stars! I hope it can help you as much as it has helped me.Since I purchase most items on on-line. I rely heavily on the feedback of other people when making my own choices. Therefore I view leaving straightforward and useful reviews as a RESPONSIBILITY and take it quite seriously. I am NOT paid to give reviews, nor do I have ANY relationship with any seller. These are my own opinions, based on my own experiences and my own or a member of my household's use of this product. I hope you find this review helpful. If you agree, please click the YES below so that I know I have helped you. If I left out any information you could use for your own purchase decision please leave a comment and I will respond as quickly as possible. Thank you.