Really large eye mask.
I have been using eye masks for years.  This is the largest one I have ever tried.  It does a good job locking light, and it is soft and comfortable.  Since it is not as contoured as some I've used,  it does let some light in through the bottom.  Like most masks, the elastic strap can slip or become uncomfortable.  I gave it 4 stars because it is better than the cheaper ones I've used.
Rating: 4 stars