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Leading eye health experts warn eclipse viewers put sight at risk

Schools and workplaces urged to pass on information to pupils and staff to prevent eye damage

Leading Eye Health Experts[1] have issued a public health warning about the dangers of looking directly at the Sun during the solar eclipse on 20 March 2015.

The magnitude of Friday’s eclipse, which will see between 82 per cent and 98 per cent of the sun obscured over the British Isles, has not been witnessed in the UK since August 1999 when a number of people suffered retinal damage as a result of looking at the sun – some of them for only a matter of seconds[2].

Looking directly at the sun, even for a moment, can lead to irreversible damage to the eye, solar retinopathy – a photochemical reaction that damages and destroys the light receptor cells that enable us to see. The symptoms of solar retinopathy, which may not become apparent for hours or even days after exposure to the Sun, include a black spot appearing in the centre of your vision, light sensitivity and reduced visual acuity. There is no specific cure for the condition, which in severe cases can lead to permanent sight loss.

David Cartwright, Chair of National Eye Health Week, a campaign for the prevention of avoidable sight loss, explains: “Anyone looking directly at the sun during the eclipse risks causing permanent damage to their eyesight so we are urging people to enjoy this rare cosmic event by viewing it indirectly. We are also calling on schools and employers to share information about how to view the eclipse safely. Children are particularly susceptible to damage because the lens of a child’s eye allows 70 per cent more light to reach the retina than in an adult[3]. Many parents will be on the school run when the eclipse begins so its vital they are equipped with sound advice about how to observe this spectacle.”

The fact that the Sun may seem ‘dim’ during the eclipse does not mean it is safe to look at with the naked eye, sunglasses, smoked glass or optical instruments such as binoculars, telescopes or cameras.

The only completely safe way to view the eclipse is indirectly. You can do this using a simple homemade pinhole card.

Just take a piece of stiff card and pierce it with a pin. Stand with your back to the Sun, and hold the card up. Then, carefully adjust the angle of the card until an image of the Sun is projected. You can project the image onto the ground, a wall or a second piece of card.

Alternatively, you could use an ordinary kitchen colander to project an image of the Sun. This is great fun for kids as you can project multiple images at the same time!

It is possible to purchase special eclipse viewing solar filters, although it is vital to ensure that any filter you use is specifically made for solar observation, carries a CE Mark and that it is not scratched or damaged. Make sure you hold the special filter firmly over both eyes BEFORE looking up at the Sun, and don’t remove it until AFTER looking away. The Sun should look quite dim and the sky should be completely black - if this is not the case then DO NOT USE THE FILTER.

If you are in any doubt about eye safety you can watch the eclipse on one of the many live webcasts being broadcast from countries along the path of the eclipse.

Visit http://www.timeanddate.com/eclipse/in/uk for accurate eclipse viewing times across the UK.

[1] National Eye Health Week is supported by organisations and charities including : The College of Optometrist, The Association of Optometrists, Federation of Ophthalmic and Dispensing Opticians and Fight for Sight.

[2] British Ophthalmological Surveillance Unit. In 39% of patients presenting to hospital ophthalmologists after the 1999 eclipse, the time spent looking at the eclipse was reported to be less than 60 seconds

[3] The Vision Centre, Los Angles Children’s Hospital