Plan to view the eclipse? Take care to prevent eye damage
Much of the country is abuzz ahead of the upcoming solar eclipse on April 8. Western Pennsylvania will be in the spotlight, too, as the Pittsburgh region will experience a partial eclipse with 95% totality while Erie will be in the zone of 100% totality.
While you’re making plans to view the eclipse, eye doctors explain how to do so safely.
“Although we’re excited to witness a solar eclipse, we want to ensure that our eyes are well-protected from any damage it could cause,” says Dr. Sarah Zambotti, an optometrist with Allegheny Health Network (AHN) Ophthalmology. “Looking at the sun without protective eclipse glasses supported by the American Astronomical Society could cause solar retinopathy or photokeratitis – retinal injuries caused by a photochemical reaction.”
How does damage occur?
Damage to the eye can happen in as little as a few seconds when looking directly at the sun. Factors such as the size of your pupil or how intense the sun’s ultraviolet light is depending on weather conditions can make a difference, but damage may still happen quickly.
When looking directly at the sun during an eclipse, the sun’s ultraviolet light enters the eye through the pupil and is focused on the back part of the eye known as the retina. The macula is one of the most important structures in the retina, as it is responsible for providing central vision as well as the ability to see clearly.
“This tissue absorbs the intense UV light, which can destroy cells in the macula, more commonly known as rods and cones,” Zambotti said. “This oxidative damage is called solar retinopathy. The visual symptoms this can cause include blurring or loss of central vision.” Photokeratitis happens when the ultraviolet light from the sun is absorbed by the cells on the front surface of the eye, known as the cornea. “Once the cells absorb the intense light, they begin to atrophy and slough off,” Zambotti said. “This is equivalent to having a sunburn on the eye and can be very painful. Visual and ocular symptoms can also include blurring of vision, redness, irritation and tearing.” Onset of both conditions is typically delayed, starting anywhere between 30 minutes to 12 hours after exposure.
Zambotti has seen patients with these conditions mostly resulting from incidents in which proper eye protection was not worn or failed during welding accidents or with the use of tanning beds. Photokeratitis can also happen in areas of the world with high elevation and thin air and is more commonly known as “snow blindness,” caused by intense ultraviolet reflections off snow or ice.
How to view safely
What do you need to keep your eyes safe? Solar eclipse filters that meet the ISO 12312-2 standard are 100,000 times darker than normal sunglasses and will filter damaging UV rays from the sun to best protect ocular health. They can be purchased at many places online but also at local optical health providers and other reputable retailers. Be sure to check that they have the ISO 12312-2 marking and are not damaged, bent or scratched in any way. The glasses should be worn 100% of the time while viewing the sun and eclipse. Homemade viewers are less safe if not made or used properly and can lead to unintended eye damage.
Pennsylvania Attorney General Michelle Henry is warning consumers to beware of scammers selling illegitimate eclipse viewing glasses that do not have proper filters.
Scammers have been capitalizing on growing consumer demand to buy eclipse glasses, and the American Astronomical Society warns that fake glasses have flooded the market.
Zambotti urges parents to make sure kids’ eyes are protected while watching the eclipse. “Please ensure that if children are viewing the eclipse with you, that they also understand the importance of wearing proper eye protection during the entire duration of the eclipse,” she said. “Removing the eye protection too early, or while still looking at the sun, can lead to unwanted UV light exposure. I also recommend that if you are planning to spend time outdoors in the sunlight before or after eclipse viewing, you continue to take precautions around general UV protection, including wearing sunscreen, hats, and sunglasses prior to the event.”
One important warning: Sunglasses are NOT an acceptable form of eye protection to view the eclipse. Solar glasses are 100,000 times darker than sunglasses and are the only way to ensure eyes are protected. The only safe way to look directly at the sun is through special-purpose solar filters or handheld solar viewers.
Other recommendations to safely view the eclipse:
– Be sure your viewing glasses are marked with the international safety standard – certification number ISO 12312-2. This number will be on the glasses’ frame.
– Read safety information on solar viewers and filters on the American Astronomical Society’s website at https://eclipse.aas.org/.
– Ordinary sunglasses – even darkly shaded ones – should not be used as a replacement for eclipse viewing glasses or handheld solar viewers.
– Do not watch through a phone camera, camera lens, binoculars or other recording devices, as these can magnify UV light and damage the retina.
– If you do use a camera or telescope, be sure your lens has a solar filter.
– Stay inside if you have prior eye or macular conditions.
– If you experience prolonged redness, watery eyes, eye pain, blurred vision, or sensitivity to light after watching the solar eclipse, contact your eye doctor to assess for damage.