Blue light glasses for gaming: which lens should you play with in the evening?

What happens in your body when you play late?

Light in the evening tells the brain it is still daytime. The signal travels through special cells in the retina to the body's internal clock, and it holds back melatonin, the hormone that marks the start of night. In a 2001 study in the Journal of Neuroscience, researchers tested 72 people across 627 sessions and found that wavelengths between 446 and 477 nm, which is blue light, were the most effective at switching melatonin off.

How much a screen matters depends on how long you sit in front of it. In a 2013 study in Applied Ergonomics, 13 participants used tablets at full brightness between 11 pm and 1 am. After one hour, melatonin was 7% lower, a difference that was not statistically reliable. After two hours it was 23% lower. A gaming evening is rarely shorter than that.

Is it the screen or the game that keeps you awake?

Both, and the research separates them. In a 2005 study in the Journal of Sleep Research, seven young men played an exciting computer game or did simple tasks, on a bright or dark display, from 11 pm to 1.45 am. After the game they took longer to fall asleep and had less REM sleep. Screen brightness on its own did not affect sleep.

A 2013 Australian study had 17 teenage boys play a fast action game for 50 or 150 minutes before their usual bedtime. The long session led on average to 27 minutes less total sleep, 7% lower sleep efficiency and 17 minutes longer self-reported time to fall asleep. Heart rate did not differ between conditions, so the researchers could not point to arousal as the explanation.

Short sessions seem to matter less. In 2014, 16 teenagers used a tablet for one hour before bed with a bright screen, a dim screen or a blue-filtered screen. Time to fall asleep and sleep stages did not differ, and the differences in pre-bed alertness were small. The takeaway is simple: a lens deals with the light. It does not shorten a match.

What happened when teenagers wore orange glasses in front of an LED screen?

The study closest to an ordinary gaming evening was published in the Journal of Adolescent Health in 2015. In it, 13 boys aged 15 to 17 wore orange or clear glasses from 6 pm until they fell asleep, for a week at home and then one evening in the lab with three hours in front of an LED screen at maximum brightness. At home they spent about 3.5 hours a day in front of screens.

With orange glasses, the screen's effect on melatonin was dampened, and melatonin was higher from 90 to 5 minutes before sleep. Participants felt sleepier late in the evening. Sleep stages and next-morning sleep quality did not change. And one more thing that matters if you play: with the orange glasses, reaction times were slower and they missed more signals in an attention test. The glasses in the study let only about 30% of light through.

Which lens should you play with?

It depends on when you play and what you play. The colour decides how much of the spectrum is filtered out, and so how much of the screen's colour you keep.

The yellow lens is made for daytime and changes colours the least. The orange lens covers the blue band but lets more of the rest of the spectrum through than the red, so you can read the map, the interface and your opponents. The red lens takes in part of the green and makes everything warm and muted. It fits once you have put the controller down, not in a ranked match. If you play competitively late, keep the study above in mind: a darker lens came with slower reactions.

How do you set up a gaming evening?

• Get daylight in the morning. How sensitive you are to light in the evening depends partly on how much light you got during the day.
• Put the orange lens on when the evening session starts, or when the sun goes down.
• Turn screen brightness down and switch off the ceiling light. The lens does most on top of less light, not instead of it.
• Decide in advance when the last match is. In the 2013 study, length was what separated the conditions.
• Switch to red when you stop playing and keep them on until the light is off.

For the whole evening as a checklist with sources, see The Evening Routine. The mechanism is covered in Blue light and melatonin.

What do we not promise?

The 2023 Cochrane review pooled 17 studies with 619 participants. It found that blue light lenses may give no short-term benefit for tired eyes, and that the effect on sleep is unclear. We take that conclusion seriously: we do not promise better sleep, faster reactions or fresher eyes. We publish what the lens filters, in which band, and what the studies show.