MYSTERY WIRE — Aviation glasses called “foggles” are usually used in pilot training — a way to get new pilots to put their attention on their instrument panel.

The War Zone reports that those glasses have another use — visitors to Area 51 are sometimes fitted with foggles to limit their field of vision.

It’s a bit like putting blinders on a horse. They only see straight ahead, and fewer distractions keep them calm.

Here’s what they look like:

Popular Mechanics suggests the use of foggles is “especially strange,” because anything that is truly secret would be hidden anyway.

The history of Area 51 is filled with accounts of secrecy and efforts to keep people out. Even workers deal with extreme security measures, such as blacked-out windows on the JANET planes that bring people to work, and buses with blacked-out windows inside the perimeter.

Details like this add fuel to the fire behind the lore of the secretive base. Things like the #StormArea51 event in September play on resentment over the military’s refusal to let people in on the secret. Odd practices like the “foggles” report draw more attention to the secrecy.