I have a neighbor who has a motion sensor light that shines on my bedroom window and goes off and on at all hours of the night.  Yes...one of those types of neighbors!  We have hung sheets on that window on top of the blinds and it helped, but nothing has helped as much as this window film blocking that pesky light.  We applied with soapy water and a month later it is still sticking beautifully.  I sleep much better because of it.    

Pros: great coverage
Cons: none