On August 21, more than 300 million people across the United States will witness an eclipse of the sun for the first time in 99 years, when the Moon passes in front of it casting darkness across swathes of the Earth’s surface.
The total solar eclipse is expected to occur across 14 states in the continental US along a 70-mile-wide swathe of the country.
Everyone in North America, parts of South America, Africa and Europe – including the UK – will see at least a partial solar eclipse, where the moon covers only a section of the sun.
However, 14 states across the United States will experience a total solar eclipse with more than two minutes of darkness descending in the middle of the day – over the course of 100 minutes.
It will be visible in parts of England, Wales, Scotland and Northern Ireland from around 7.35pm BST.
With the cosmic phenomenon only weeks away, a number of “unscrupulous companies” have emerged to take advantage of the excitement by selling unsafe solar glasses online.
The consequences for picking the wrong pair could be devastating, causing solar retinopathy and blindness.
Dr. Omar Punjabi, a North Carolina board-certified ophthalmologist, said: “Unfortunately, the damage to the nerves and the tissue which is the retina tends to be permanent.”
With even websites like Amazon falling victim to the fakes, NASA has issued its list of recommended retailers and a list of how to check your glasses thoroughly to ensure you will not damage your vision.
Eclipse viewing glasses and handheld solar viewers should meet all the following criteria:
· Have certification information with a designated ISO 12312-2 international standard
· Have the manufacturer’s name and address printed somewhere on the product
· Not be used if they are older than three years, or have scratched or wrinkled lenses
· Not use homemade filters
· Ordinary sunglasses – even very dark ones – should not be used as a replacement for eclipse viewing glasses or handheld solar viewers.
The space agency has reminded eclipse watchers to ensure their purchase was manufactured by one of only four NASA-approved companies: American Paper Optics, Rainbow Symphony, Thousand Oaks Optical, and TSE 17.
You should wear your glasses through the majority of the event, only taking them off when the moon completely blocks the sun.
NBC Charlotte Chief meteorologist Brad Panovich said the fakes often look authentic, and it was vital to check your purchase with care.
He said: “A lot of them are flooding…