These oxygen eye masks were easy to put on and use and I was able to sleep with them on, so they are comfortable to wear. I used a pair overnight and when I removed them in the morning they did an okay job at taking away some of the darkness under my eyes. My under eye area appeared lighter than it was when I put them on. I don't believe that any product would wipe out the dark cycles completely but this one did a fairly good job at removing a lot of it. All in all I am pleased with this product and will be using it again.