It can be tempting to cast your eyes skyward to watch next week’s solar eclipse, but eye experts and the folks at NASA all warn: Don’t do it.
Cayman will witness a partial eclipse in the early afternoon of Monday, Aug. 21, when 55 percent of the sun will be blocked by the moon. In America, a total eclipse will be experienced across the country.
Whether a total or partial eclipse, viewers of the phenomenon face the same risk if they do not take precautions to protect their eyes.
Optometrist Mellisa Hudell, from Optical Outlook in Grand Cayman, explained that staring at the sun during an eclipse can cause a severe condition called solar retinopathy, which occurs when bright light from the sun floods the retina on the back of the eyeball.
“The retina is home to the light-sensing cells that make vision possible,” Dr. Hudell said. “When they’re over-stimulated by sunlight, they release a flood of chemicals that can damage the retina. This damage is often painless, so people don’t realize what they’re doing to their vision.
“Solar retinopathy can be caused by staring at the sun. Few people can stand to look directly at our nearest star for very long without pain, even though it is 93 million miles away. It does happen occasionally – medical journals record cases in which people high on drugs have stared at the sun for long periods of time, causing serious damage.”
However, during a solar eclipse, the temptation to stare at the sun can prove irresistible to some.
“With the sun almost covered, it’s comfortable to stare, and protective reflexes like blinking and pupil contraction are a lot less likely to kick in than on a normal day,” Dr. Hudell said.
She cited a study conducted after a solar eclipse in Europe, when 45 patients with possible solar retinopathy showed up at an eye clinic in Leicester in the U.K.. Forty were confirmed to have some sort of damage; five of those had visible changes in their retinas. Twenty of the patients reported eye pain, while another 20 reported problems with vision. Eventually, 12 reported that their sight had returned to normal seven months later, but four could still see the damage in their visual field, such as a crescent-shaped spot.
On its Eclipse 2017 website, NASA states: “The only safe way to look directly at the uneclipsed or partially eclipsed sun is through special-purpose solar filters, such as ‘eclipse glasses’ or hand-held solar viewers.”
The space agency advises that homemade filters or ordinary sunglasses, even very dark ones, are not safe for looking at the sun, as “they transmit thousands of times too much sunlight.” Any pair of eclipse glasses or solar viewer should comply with ISO 12312-2 international safety standards, experts advise.
NASA advises the following:
- Always inspect your solar filter before use. If scratched or damaged, discard it. Read and follow any instructions printed on or packaged with the filter
- Supervise children using solar filters
- Stand still and cover your eyes with your eclipse glasses or solar viewer before looking at the bright sun. After looking at the sun, turn away and remove your filter – do not remove it while looking at the sun
- Do not look at the uneclipsed or partially eclipsed sun through an unfiltered camera, telescope, binoculars, or other optical device
- Do not look at the sun through a camera, a telescope, binoculars, or any other optical device while using your eclipse glasses or hand-held solar viewer – the concentrated solar rays will damage the filter and enter your eye(s), causing serious injury
- Seek expert advice from an astronomer before using a solar filter with a camera, a telescope, binoculars, or any other optical device. Solar filters must be attached to the front of any telescope, binoculars or camera lens
Members of the public are invited to attend a partial solar eclipse viewing at the University College of the Cayman Islands on Monday, when the eclipse will be visible from between 12:38 p.m. and 3:26 p.m.