Hail Longbough, from the land of the Midnight Sun... we had two months straight of BRIGHT nights, with the sunlight managing to sneak around the edges of even our darkest curtains (the pull-down/snap-up kind, which you can buy as a "roll" at IKEA, btw). It kind of drove me insane.
But I managed to survive by using a plain old eyemask from a Lufthansa flight a couple of years back. It's the standard-issues complementary airline mask, with black cloth on the inside and dark blue on the outside. It was light enough on my face that I didn't really notice it. Do you have any old travel masks from the airlines, or perhaps stop in the travel section at Target?
Other than that, I recommend the near-blackout shades from IKEA, if you can get them. Or just tie a scarf around your head.
