The downstairs windows were original to the house and the double pane windows were no longer sealed. If you cleaned the windows inside and out there was still a film between the glass. I had the windows re-glazed with Low E double pane glass. You can't really show a picture of nice clean new glass so I just have a picture of the windows before showing the film between the glass that was clearly visible when the sun hit the glass in the mornings and afternoon.
Not shown but it is a really clear view.