White spots on Nikon lens

[John Soliven]

I've noticed this "white spots" inside of my Nikon lens specially on ultra wide angle lens. I saw it on my Nikkor 16-35 f4 and now on the Nikkor 14-24 f2.8. But not on my other lenses (prime, zoom, telephoto).

I know this doesn't affect the lens performance. I'm just wondering why is it only appears in UWA. Have you also notice this on your Nikon UWA lenses?