Thousands of skygazers throughout the UK witnessed today's breathtaking solar eclipse. Earlier this evening, the Moon positioned itself directly between Earth and the Sun, obscuring the Sun's face. While Britain experienced a partial solar eclipse, it's been described as the most substantial in decades, with over 90% of the Sun's surface covered.
Eye care specialists have now issued guidance on what steps to take if you gazed at the sun without adequate protection, and when professional optometric advice becomes necessary.
Risks of Looking Without Protection
Nkosi Yearwood, optometrist and The College of Optometrists council member for Wales, said: "People often forget that the sun gives out a lot more light than just visible light. There are also ultraviolet rays, infrared rays, and it's this whole spectrum that is harmful to our eyes."
"Because the sun starts dimming in the eclipse, many people think that it's safe to look at, but actually even if it's a 90% coverage, you've still got 10% of the sun that you're staring at, and that's still a lot of energy."
Patrick Laidlaw, an optometrist based at Optegra Eye Clinic Sheffield, explained: "If you look directly at it, it can cause damage to the back of the eye and can cause some retinopathy. If you look at it for too long you could even develop a central bit of field loss."
This is because looking directly at a solar eclipse can affect the macula. "There's a point at the back of the eye called the macula, which is where you get your central vision from, and it's highly populated with photoreceptors. Intense light can cause toxicity and can essentially burn the back of the eye," explains Laidlaw.
Symptoms and When to Seek Help
Yearwood notes that history suggests that this damage can occur even when you look at it for a short period of time. "In the days following the last eclipse in the Nineties, around 70 people across the UK presented to eye departments with some level of solar retinopathy, and about 40% of these people looked at it for less than a minute," says Yearwood.
People tend to get delayed symptoms. "It can take a few hours or even couple of days before you start feeling the symptoms," says Yearwood. He explains that many people don't notice it straight away because there usually isn't any pain associated with it. "The retina doesn't have any pain receptors, so you can do this damage and not know about it," says Yearwood.
However, there are other signs to look out for that can range from mild to drastic. "The main things to look out for is any blurring in vision, distortion, a dark spot or a change in your colour vision," says Yearwood. "If you experience any of these symptoms or just feel like things aren't quite right, seek advice from an optometrist at your local opticians straight away."
Laidlaw adds: "I would also look out for any severe light sensitivity or any reduction in vision."
Diagnosis and Recovery
What do optometrists look for? Yearwood says: "We look for any changes to the macular region, because that's the part of your eye which focuses on the very fine detail. Whenever you're looking at something, your macula is focused on it, and we tend to see changes to the retinal cells. It generally shows up as a yellowish spot."
There is no treatment for this damage, but it can heal itself. "Similar to sunburn, it does in most cases does heal itself," says Yearwood. "The length of time to heal and how high the chance of healing depends on how long you look at the eclipse for. So, if you did end up staring at it for too long, you do risk permanent vision damage. If you are worried, go to your local opticians and let them assess you."
