Blue-light glasses: hype or helpful? What to know before you buy

Blue-light glasses are a £100-million industry built on two promises: less eye strain and better sleep. One of those claims is shaky; the other has a kernel of truth — if you buy the right thing. Here is the honest breakdown.

The eye-strain claim

This is the weaker one. Large reviews have found little evidence that blue-light-filtering lenses reduce digital eye strain. The tired, dry eyes you feel after a screen day are mostly caused by not blinking enough and staring at a fixed distance — not by blue light itself. A pair of clear filtering glasses will not fix that.

The genuinely effective fix is free: the 20-20-20 rule — every 20 minutes, look at something 20 feet away for 20 seconds — plus deliberately blinking.

The sleep claim

Here there is more to it, with a crucial caveat. Bright light in the evening — especially blue-heavy light — suppresses melatonin and pushes your body clock later. Blocking it can help you wind down. But the lens colour matters:

• Clear “blue-light” lenses block very little of the relevant wavelength. Largely cosmetic for sleep.
• Amber or orange evening lenses block far more and are what the supportive studies actually used.

So “blue-light glasses help you sleep” is only true for the proper amber kind, worn in the 2–3 hours before bed.

If you still want a pair

Buy for the job:

• For evening wind-down, get amber/orange lenses, not clear ones.
• For daytime screen comfort, save your money and fix your habits instead.

Cheaper than any glasses

Before you buy anything, try the free options: switch devices to night mode, dim your home lights after sunset, and keep bright overhead lights off in the last hour. These do more for your sleep than any clear lens.

The bottom line

Blue-light glasses are oversold for eye strain and under-specified for sleep. If sleep is your goal, skip the clear “computer glasses” and get proper amber lenses for the evening — or just dim your world and switch on night mode for free.