The reading room
What the research says
We sell blue light glasses, so you are right to be sceptical of us telling you they work. Here is the independent evidence instead, including the parts that do not flatter the product. Every link goes to the original source.
Where the evidence is strongest
Light at night, and your sleep
Evening light exposure shifts your body clock. This is the best-established reason to think about blue light at all, and it is about when you look at a screen more than what you wear.
- Harvard Health Blue light has a dark side Harvard researchers compared 6.5 hours of blue light against green light of the same brightness. Blue light suppressed melatonin for about twice as long and shifted circadian rhythm roughly 3 hours, against 1.5 for green. Harvard suggests avoiding bright screens 2 to 3 hours before bed, and says people on night shifts or using devices at night may consider blue-blocking glasses. Read at the source
- Sleep Foundation Blue light and sleep A plain-language overview of how light exposure interacts with the sleep-wake cycle, and practical steps for the hours before bed. Read at the source
The honest part
What the trials say about eye strain
Blue-light filtering lenses are widely sold as a fix for tired eyes. The best available evidence does not support that, and we would rather you heard it from us.
- Cochrane systematic review, 2023 Blue-light filtering spectacle lenses in adults Pooling 17 randomised trials across 619 people in six countries, the reviewers concluded blue-light filtering lenses probably make little or no difference to eye strain during computer use in the short term, and no measurable difference to corrected vision. Effects on sleep quality were inconclusive. They also found no consistent reports of adverse effects, with any that occurred being mild and temporary. Read at the source
- American Academy of Ophthalmology Should you be worried about blue light? The Academy does not recommend blue-light blocking glasses for screen use. Its position is that digital eye strain comes from how we use screens, chiefly blinking less and focusing for long stretches, rather than from the blue light itself. Read at the source
Practical and free
Looking after your eyes at a screen
The advice that carries the most agreement across eye-care bodies costs nothing and takes twenty seconds.
- American Optometric Association The 20-20-20 rule Every 20 minutes, look at something about 20 feet away for at least 20 seconds. It gives the focusing muscles a rest and prompts you to blink, which is the part most people lose at a screen. Read at the source
- Brown University Health Digital eye strain and how to relieve it A clinical explainer on dry eye and fatigue from screen work, and the adjustments to lighting, distance and breaks that tend to help. Read at the source
Not in dispute
Sun, UV and your eyes
Under an African sun this is the one worth taking seriously. The link between ultraviolet exposure and eye damage is well established, and the protection is simple.
- American Academy of Ophthalmology The sun, UV light and your eyes UV exposure raises the risk of cataracts, growths on the eye such as pterygium, and cancers of the eye and eyelid. Damage accumulates over a lifetime, which is why protection matters long before symptoms appear. Read at the source
- American Academy of Ophthalmology How to choose sunglasses Look for 100% UV or UV400, which blocks both UV-A and UV-B. Darker lenses are not automatically better; wraparound or oversized shapes help by cutting light entering from the sides. Price and protection are not the same thing. Read at the source
How we read all this
Two things follow from the evidence above, and they point in different directions.
For sunglasses, the case is settled. UV exposure damages eyes over a lifetime, and every pair we sell blocks it. That is protection you can rely on rather than a preference.
For blue light glasses, be your own judge. The trials do not show a reliable effect on eye strain, and we are not going to claim otherwise. Where there is a real mechanism is evening light and sleep, which is why Harvard raises blue-blocking lenses for late device use specifically. Plenty of our customers find them comfortable for long screen days. That is a personal preference, honestly described, not a medical promise.
None of this is medical advice, and no pair of glasses replaces an eye test. If your eyes hurt, water, or your vision changes, see an optometrist.