Brits have been warned not to look directly at the sun during today's solar eclipse as a doctor reveals the key signs of potentially serious eye damage.
Retina Damage Risk
Dr Azeem Majeed, a GP, said even a few seconds of staring at the sun without protection can damage the retina. The main danger is that people may not immediately realise they have injured their retina because it does not have pain receptors.
Dr Azeem said: "The symptoms won't often occur straight away, so this is the risk people have, people look at the sun, the damage of the retina, but don't actually realise they've got a problem until perhaps a few hours later."
Understanding the Retina
The retina is a thin layer of light-sensitive tissue in the back inner part of the eye. It works like the film or digital sensor in a camera by catching light and turning it into nerve signals that the brain translates into images.
Possible warning signs of a damaged retina include blurred vision, blind spots, distorted sight and reduced colour perception.
Dr Azeem said: "What you might find is that you've got blurred vision, and then in more severe cases you'll have a blind spot, potentially where the retina was damaged, or distorted vision, reduced perception of colour, these kind of problems."
Permanent Damage Possible
He added that damage can be permanent in more serious cases.
Dr Azeem said: "Unfortunately if the retina is damaged you can't really correct that. If you've got very minor changes, you look at the sun for a second, you might recover, but if you look at it for any period of time, unfortunately it's unlikely those changes would improve very much in the future."
He also stressed that people may not feel anything while the damage is taking place.
"Bear in mind is the retina has no pain receptors, so people won't feel any pain as the damage is happening," he said.
Safe Viewing Advice
Unlike some other countries with a full solar eclipse, the UK will only see a partial eclipse, meaning the sun will not be completely covered by the moon.
"Even that 10-20% [of peaking sun] is enough to cause damage," he warned. People with existing eyesight problems may be particularly vulnerable to further deterioration, although those with normal vision can also suffer retinal damage if they stare at the sun.
Britons have been advised to view the eclipse using specialist eclipse glasses.
If you did not manage to buy these, Dr Azeem said a simple way to watch safely is to "create a small hole in a piece of paper and then use that to direct the sun rays to another piece of paper, so you can see the eclipse, but not directly."
Despite the risks, the doctor said he hopes only a small number of people would experience problems following the eclipse, adding that the potential health issues had been "well publicised" in the media.
