I think they might be sweat glands. I have them too and for the longest time, I had the impression they were milia seeds until I saw a derm who told me they were sweat glands. I have quite alot of them under my eyes, and they seem to be increasing. I had wanted to laser them off, but my derm advised against it as she said firstly, they are not big enough to be a real cosmetic disturbance and second and more importantly, lasering leaves a scar so she wouldn't advise lasering unless the white bump is big and obvious enough. I have about one or two on the area just outside my eye that the derm deems big enough for laser to remove them, but I decided against it because it wasen't really that obvious anyway (in my opinon) when its just a lone one (its the effect of them being in clusters that affects me), and the cost just didn't seem worth it.