Difficult to explain and not seen anything on internet about issue but my upstairs bay window is made up if 5 panes with the georgian white bits built in. Anyway last year i noticed a few spots on one of the panes noticeable when the sun shines in. It looks to be inside the pane as cannot feel any lumps or bumps from inside the house or externally. So little tiny dots can be seen which obscure the view out. This year the whole pain is covered and is like some infectious disease. Anyone come across this before and know what i am trying to say? Its difficult because the glass is not cracked just full of spots for the want of a better way of putting it.