Solar eclipse glasses have sold out across Scotland, making it virtually impossible to have them delivered in time for this evening, even from major online retailers. However, those eager to witness the first near-total solar eclipse in the UK since 1999 can still do so safely through a number of alternative methods.
Eclipse timing and glasses shortage
The celestial event is set to kick off at around 6pm today (August 12), reaching its peak shortly after 7pm before drawing to a close at approximately 8pm. Precise timings will vary depending on your location across the country, reports the Express.
Specialist glasses have been snapped up ahead of the occasion, with convenience stores, national parks and the Royal Observatory Greenwich all selling out of their stocks. The observatory alone has shifted approximately 15,000 pairs over the past month.
Experts have urged the public not to be tempted by "knock-off" alternatives or to resort to ordinary sunglasses. Eclipse glasses must meet the ISO 12312-2 safety standard, as uncertified versions could leave eyes dangerously exposed to harmful solar radiation.
Health risks of direct viewing
Mohamed Elalfy, consultant ophthalmologist and president of the Royal College of Ophthalmologists, said: "The safest way to enjoy the eclipse is to observe it indirectly, such as by watching a live broadcast."
"Looking directly at the Sun during a solar eclipse can cause damage to the retina, potentially damaging the cells responsible for sharp central vision. Crucially, the retina has no pain receptors, so people will not feel the damage as it happens."
The risk was emphasised following the UK's 1999 total solar eclipse, when the Royal College of Ophthalmologists reported approximately 70 cases of individuals experiencing vision problems after viewing it. Around 40% had gazed at the eclipse for less than a minute.
Symptoms can take several hours to emerge and include "blurred vision, a central blind or dark spot, distorted vision, reduced colour perception and increased sensitivity to light". Mr Elalfy added: "While some people recover over weeks or months, others can be left with permanent visual impairment."
Safe viewing methods without glasses
One of the easiest alternatives requires nothing more than a kitchen colander. Rather than looking towards the Sun, observers can use its holes to project images of the eclipse onto the ground or another surface.
Imo Bell, a planetarium astronomer at the Royal Observatory, explained: "You can project the image of the eclipse using a household item like a colander which has lots of holes in - point the colander towards the Sun with your back facing it, and in the shadow of the colander you'll be able to see the eclipse in the holes, which is really cool."
A pinhole projector presents another alternative and can be fashioned from a single sheet of card, while a more elaborate version can be built using a cardboard box. Even trees can serve as a means of witnessing the spectacle. UK Health Security Agency guidance states that gaps between leaves can project images of the Sun in much the same way as the holes in a colander. Onlookers should turn their backs to the tree and watch the eclipse appear in the shadows cast through the gaps.
Telescopes and cameras
Kyla Black, Boots Opticians director of optical practice, said: "Budding astronomers who will be looking through cameras, binoculars or telescopes at the eclipse must make sure they have approved solar filters attached. If you're not sure your telescope does, then contact the maker of the product to ensure you know you'll be safe."
Local astronomy centres may also be hosting viewing events using suitably filtered telescopes, offering yet another option for those who have been unable to get hold of eclipse glasses in time.
