I recently learned of this as well. I had no idea until someone mentioned it in conversation.
Originally Posted by Mainecoonmaniac
Some of the info I've read said that they can be up to 3mR/hr, which as I understand it means that the lens would have to be in your pocket, 8 hours a day, 40 hours a week, for 6 months straight before you'd have the recommended annual "dose".
In any event, if there is in fact two of them, I'm hoping to trade/sell one for a Pacemaker SG body - since I sold my SG back in January.