I have them too, since last preg 5 years ago! And they ain't going :(
They are called Milia and are caused by a build-up of hardened serum. Nicked this from a 'ask the doc' site on the interweb. Don't recommend his advice about using a facial scrub if they're under your eyes though...
''Milia are small, white (or sometimes pale yellow) spots that usually appear around the eyes, on the cheeks and on the eyelids. No one really understands why they appear or why some people get them while others don't.
They're a type of cyst filled with a substance called keratin, a protein that provides strength to the skin. Milia don't appear to be related to different lifestyles or diets and are certainly not infectious or caused by poor hygiene.
Apart from making people worry about their appearance, milia aren't harmful and don't need to be treated in any way.
However, if you do want to get rid of them, the following may help:
Hold a hot, wet face cloth over the skin for a few minutes - the temperature should feel comfortable, not painful. This simple facial sauna helps to loosen and remove dead skin cells and debris from the skin.
Use an exfoliating facial scrub to remove the top layer of skin, which can enable the cysts to fall out. These scrubs are available from the pharmacist and are the kind of facial wash used for treating mild acne. Those containing salicylic acid work well, but always read the label or ask the pharmacist to make sure the one you select is suitable for you.
You may wish to have a consultation with a qualified beautician who'll also be able to recommend possible treatments.
Most importantly, resist the temptation to pick at them. This will hurt, or damage the skin''