Most sleep mask research tested masks and earplugs together in intensive care, and the one home study of masks on their own found no change in how sleep was structured. Here is what the evidence shows, what it doesn’t, and who a mask is most likely to help.

Mulberry, momme, 6A, pure silk: most of the words on a silk mask label describe the fabric, not the darkness. Here is what each one means, what silk does better than cotton and satin, where it doesn’t, and how to check a mask is real silk.

Most light reaches your eyes around a sleep mask, not through it. Where the leaks are, what closes them and a two-minute torch test for total darkness.

Light and noise wake people through different routes, so one device rarely covers both. Here is who benefits from wearing a sleep mask and earplugs together, whether a matched set beats separates, and how to wear the pair comfortably on your side.

Blackout curtains darken the whole room but leak at the edges, while a sleep mask covers your eyes wherever you sleep. When each one wins, how to make a bedroom darker for little money, and when to use both.

Satin is a way of weaving, not a fibre, so a satin eye mask can be polyester or silk. Here is how the two compare on feel, warmth, static, washing and price, and how to read the label before you buy.

After a night shift, daylight is the main thing standing between you and sleep. Here is how to keep the light low from the journey home to waking, where blackout curtains fall short and where a sleep mask fits in.

Contoured masks keep fabric off your eyelids and lashes; flat masks are thinner, lighter and pack smaller. Here is how each shape seals out light, how it copes with a pillow, and which suits back, side and front sleepers.

Twenty minutes in the fridge in a clean bag, never the freezer, turns a silk sleep mask into a cold compress for a puffy morning. Here is how to do it, how long to wear it, and how it compares with a gel mask and a cool flannel.

Light at night delays and suppresses melatonin. The bedroom light sources that matter most, ranked, with the simplest way to darken each one.