vision strip
n.β Β«Indeed, during the 1970s, many districts, including San Diego Unified, began to construct new schools with no windows. Educators argued that windows prevented students from concentrating; architects of these schools created βvision strips,β as they called them, thin slots at the tops of the walls that allowed some light to come into the room, but nothing else.Β» ββGoing beyond No Child Left Behind” by Richard Louv San Diego Union-Tribune (California) Jan. 31, 2006. (source: Double-Tongued Dictionary)