I use "lightbook" and it works.

It may be too late to start this therapy however. It is usual that one starts using the light before the days significantly shorten. I start using mine in early October and right through until end of March.

15 minutes is about average. For those unaware, you don't look into the light. Rather, you offset the lamp. You place it beside you and continue with your usual activities like using your computer/tablet, or reading, etc.

I have had great success using my light therapy lamp with regards to the seasonal depression I used to suffer from. I also use it when I wish to be soothed.

The lamp need not be large. My litebook is small enough to carry in my purse.