UPDATE: Per comments below I see the flaw in my question now.
In the Doctor Who episode The Witch's Familiar, we learn that the Doctor has:
traded in his sonic screwdriver for a pair of sonic sunglasses
Are there any technological advantages to utilizing this style of device or is it merely a cosmetic change, similar to each Doctor who has gone before him?
Further, what happened to his previous sonic screwdriver?
Is this possibly the one that we find later in the hands of River Song?