Types of freckle.

[sezchwarn]

Hi, I used to have lots of facial freckles that came in the summer and faded in the winter. Since going abroad without sunscreen they have developed into freckles that remain dark throughout the year. I was just wondering if anybody knew how the two types differ (apart from in the way I just mentioned) and if they have different names. i.e. are they situated in different levels of the dermis or...
Thanks.

[sezchwarn]

I have just learnt the ones that do not fade are called lentigines as oppose to freckles/ephilides. My question has now become why do they not fade and also how do they differ in terms of depth and what they are.