What is the name of the static cling on the back of school buses to let them see below the window?

Question

I am trying to find out the name of the plastic cling that is on the back of school buses to let them see lower than the window. It allows you to see wider and lower than the window. I have seen them on Vans and also on RVs. Can anyone tell me what they are called or where to get them? Thanks

Answer 1

Static cling is a little simplistic. It is actually a lense. It is called a fresnel lense. It would be available at RV dealerships, and places that service and sell parts for them. They usually call them RV Wide Angle Lenses. The basic lense that is put on the rear windshield with water is in the $10 to $15 range.
http://www.campingworld.com/browse/skus/index.cfm?skunum=26256

Answer 2

As "Fred C" has already pointed out, it is a form of Fresnel lens that is mad up of hundreds of concentric rings of lenses which, when seen from a distance, concentrates a wide angle of vision into a compacted space.

You may also see a version of these in some of those reading lenses that magnify an entire page, or section of a page or map. Some of them are wallet sized and are about the size and thickness of a credit card. You may have seen it advertized on television.

The one for vehicles "shrinks" a wide angle for the driver to see more of an area, while the other "magnifies" a smaller space to enlarge a smaller portion.

Answer 3

Wide Angle Lenses