by Michael Smith (Veshengro)
When the sun crossed the celestial equator on the Autumn Equinox, which happened in the Northern Hemisphere (Britain) on September 23, 2014 at 02:29 GMT, the highest point on its trajectory reduced to just 40-degrees. This means that when the sun is high in the sky, such as at the height of Summer, our brow bone acts like a built in sun shade and prevents damaging UV light entering the eye.
When the sun is low in the sky, such as during the Autumn months, and still more so in winter, but also in Spring, the total amount of UV radiation your eyes are exposed to increases dramatically.
Cumulative UV exposure has been found to promote the onset of cataracts and has been implicated in the development of a range of other eye conditions including photokeratitis, pterygium and macular degeneration – the UK’s leading cause of blindness.
One simple way you can tell if your eyes are in danger of UV damage is to look at your shadow. If your shadow is taller than you, you should protect your eyes using a hat, sunglasses or UV protective lenses.
Simple strategies for staying safe in the sun
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Protect your eyes whenever the UV Index rises to three or more – even on a cloudy day. (Over 90% of UV can transmit through the clouds). For comfort you may also wish to wear eye protection on bright days when the UV Index is below three.
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Wear sunglasses with a CE; UV 400 or BS standard BSEN1836 : 2005 mark – this ensures they provide adequate UV protection.
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Make sure that your children never wear toy sunglasses. These offer little to no UV protection and can actually cause more damage because the tinted lenses dilate the pupil allowing more UV light to enter the eye.
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If you wear spectacles, check your lenses provide UV protection.
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Make sure your eyes and area around your eyes is fully covered. Large lenses and wrap-around styles provide the greatest protection.
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Wear a hat, cap or visor for added protection
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Sit or play in the shade
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Stay out of the sun between 12pm and 3pm when the sun’s rays are strongest. Up to 50% of the total daily UV is emitted between these times!
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Never look directly at the sun, this can permanently scar the retina.
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Remember the shadow rule…
… If your shadow is taller than you are your eyes are at greatest risk from UV exposure, as your brow bone no longer offers natural protection.
© 2014
