Health experts have issued a warning about the upcoming partial solar eclipse on August 12, advising the public not to rely on ordinary sunglasses. The eclipse will be visible across the UK, but looking directly at the sun without proper protection can cause permanent damage to eyesight.
UKHSA alert
The UK Health Security Agency (UKHSA) shared the alert on social media, stating: "Ordinary sunglasses - no matter how dark - allow harmful solar radiation to reach the retina and should not be used to view an eclipse. If you want to use eclipse glasses make sure they are genuine with specially designed filters that meet the international safety standard."
The agency explained why watching a solar eclipse is risky: "During an eclipse, the sun appears dimmer than usual. This makes it easier to look at directly - and that's precisely the problem. The reduced brightness can override the body's natural reflex to look away, allowing intense sunlight to reach and damage the retina. This damage happens without causing any pain, so you may not realise harm is occurring until it's too late."
Historical cases
Following the 1999 total solar eclipse, the Royal College of Ophthalmologists reported around 70 cases of people experiencing vision problems after watching the eclipse. Around 40% had looked at it for less than a minute.
Why not sunglasses
The UKHSA stressed that ordinary sunglasses do not provide adequate protection for viewing a solar eclipse. They reduce glare, making it feel more comfortable to look at the sun for longer, while still allowing harmful solar radiation to reach the retina. "Never use regular sunglasses to look at the sun during an eclipse," the experts warned.
Safe viewing methods
There are two safe ways to do this - specialist eclipse viewers or indirect viewing methods. If you want to use eclipse glasses or handheld solar viewers, make sure they are genuine with specially designed filters that meet the international safety standard ISO 12312-2:2015(E).
The UKHSA said: "Genuine eclipse glasses are available from reputable retailers, including Royal Museums Greenwich. Be cautious of products sold online that may not meet this requirement. If you're unsure whether a product is certified, don't use it. Don't use eclipse glasses if the lenses are scratched, torn or damaged."
Alternatively, you can watch the eclipse indirectly without any specialist equipment at all. Safe options include a pinhole viewer, which you can easily make at home; viewing the sun's image projected through a colander or the gaps between tree leaves; and projecting the sun's image onto a sheet of paper using a simple pinhole projector.
Whichever method you choose, make sure you follow guidance carefully. The Royal Astronomical Society has published detailed, practical advice on all of these approaches.
