Cut a head shape to fit in your window, from heavy cardboard. Cut round eye holes slightly smaller than the paper mache eyes. You can use the medium mixing bowl as a template, trace around it then cut about 3/4 inch inside the line.
Draw a horizontal line on the back of each eyeball . This is so that you can tell that they are properly oriented when gluing them in place. Place the completed eyeballs face down on the floor and place the cardboard on top. Use books to support the cardboard in a level position.
Rip one sheet of newspaper into small strips. Mix up a small batch of paste (about 1/2 cup). Use paper mache strips to glue the eyeballs in place. Make sure you cover all cracks to prevent light leaking. Leave to dry overnight.