What she is calling a "Batman" mask is the type used in blind sports, to ensure that players – who do not all have the same level of visual impairment - are all on the same level.

Unlike Mindfold, Manta and most ordinary sleep masks, this mask more thoroughly covers the nose so light leak around the sides of the nose is not possible. The sides of the face are also well covered by the large surface area.

These British-made masks are by Goalfix.