The demand for solar eclipse glasses used to safely view the rare celestial event has been ramping up as sellers, along with astronomy and eye-care experts in Canada, warn that viewing the eclipse with the naked eye is dangerous.
Jenna Hinds, executive director of the Royal Astronomical Society of Canada (RASC), says her organization has sold 70,000 pairs between August 2023 and February 2024 and sold out of its online stock in February.
“Demand is through the roof for this stuff,” Hinds said in a phone interview with CTVNews.ca. “The sooner you get your hands on a pair of solar glasses, the better.”
Robert Cockcroft, assistant professor at the department of physics and astronomy at McMaster University in Hamilton, Ont., and secretary of the Canadian Astronomical Society, says McMaster bought 600,000 eclipse glasses in mid-December, which is enough for all residents of Hamilton. About 500,000 have already been given away free of charge and the remaining ones have been mostly accounted for, he noted.
The rare celestial event will happen on Monday, April 8, in parts of Canada, the United States and Mexico. Most of North America will at least experience a partial solar eclipse. During a total solar eclipse, temporary darkness, or the moon’s 185-kilometre-wide shadow, will blanket the path where the moon aligns perfectly between the Earth and the sun.
The next total solar eclipse won’t happen until 2044 in Canada. Canada last experienced a total solar eclipse in 2008.
What are eclipse glasses?
Elaina Hyde, director of the Allan I. Carswell Astronomical Observatory at York University in Toronto, says solar eclipse viewers such as eclipse glasses are a popular way to see the phenomenon safely. She says the observatory is providing them for free at its events. These viewers or glasses must have ISO (International Organization for Standardization) certification with ISO-12312-2, indicating they meet international safety requirements, she said.
“The ISO safety rating basically means only a small fraction of light goes through into your eyes,” she said in a phone interview with CTVNews.ca.
Eclipse glasses are usually made of cardboard and have a special filter to block out virtually all light, including 100 per cent of ultraviolet and infrared light, as well as 99.9 per cent of regular light, according to astronomy experts. Hyde stresses that regular sunglasses, tinted car roofs, welder’s glasses or anything else that is not rated for viewing the eclipse safely won’t be safe to use.
“The sun is incredibly bright. This is why it can cause you to go blind,” she said. “Regular sunglasses block an average 10 per cent of light, a thousand less or several thousand times less than what is needed.”
She says most of North America will only have a partial eclipse, which means there is no time when it is safe to view the sun directly as it can lead to partial or complete loss of eyesight.
Astronomy experts say it is only safe to view a solar eclipse during totality when the moon fully covers the sun.
How much do they cost?
While costs vary online for these glasses, many companies are selling them at similar price points and don’t have significantly high costs for smaller orders. Astronomy experts say the glasses are generally inexpensive, with a pair costing $10 or less.
Hyde warns people to be aware of potential fraudsters selling counterfeit eclipse glasses. She recommends that buyers go to a reputable vendor that sells glasses and filters verified by the American Astronomical Society.
“They should not cost a lot of money,” she said in a phone interview with CTVNews.ca. “Lots of places are giving them away.”
Glasses with plastic frames, designs or claims of using better material to block out the light can cost more.
Bulk purchases end up costing less per unit on Amazon, which has discounts on certain products, and other online retailers. Ordering from foreign marketplaces like AliExpress may have cheaper prices. However, some advise against it due to questions about quality and the risk they won’t be delivered on time.
Hinds recommends people check whether places in their cities are handing them out for free. While the glasses are sold out on RASC’s website, her organization is selling a limited supply in person for cash only from its Toronto national office.
Adam Levy, president of Celestial Optical, with headquarters in Buffalo, N.Y., says demand now is “extremely high” in Canada and his company is selling the eclipse glasses “very aggressively.”
In the last few weeks, he says his company has sold about 15,000 to 20,000 eclipse glasses a day on Amazon in Canada. “The sales numbers are increasing pretty much every day,” Levy said in a phone interview with CTVNews.ca. “We expect it’s going to be a mad rush as we approach the date of the eclipse.”
After a total solar eclipse in 2017 in some parts of the United States but not Canada, which only saw a partial eclipse, Celestial Optical was formed in part to fill the gap in the Canadian market, Levy said.
Levy says his company, which sells products exclusively on Amazon in North America, has experienced a big problem with fake products that use Celestial Optical’s name and design. “There are a lot of competitors and we’ve had a big problem with counterfeiters,” he said, noting the authentic products are only sold under its name on Amazon.
Buying glasses last-minute ‘risky’
Sujatha Mathi, owner of the online store Eclipse Glasses Canada in Toronto, says sales were quiet in January, but exploded around February.
Mathi is hoping to find sponsors to donate $250 for 500 units of the eclipse glasses she plans to give for free to health-care workers and their families. She has set aside 75,000 pairs of the glasses for donations to the hospitals and sponsors can choose the hospitals.
As the date of the total eclipse approaches, Mathi says it’s best to order by March 20 to give Canada Post enough time to deliver the glasses.
“People should just be aware that leaving it to the last minute is going to be a little bit risky if they want to get those,” Mathi said.
Safely viewing eclipse
Some astronomy experts and sellers believe it is safe to view the solar eclipse only during totality when it goes dark.
However, Dr. Shaina Nensi, vice-president of the Ontario Association of Optometrists and an optometrist in Toronto, says people should avoid looking at the sun without solar filters or glasses, even during totality when the moon fully blocks it.
“The most important thing to note with solar eclipse glasses is when you look through them, you should not be able to see anything through an authentic solar filter except for sun and light equally bright as the sun,” Nensi said in a phone interview with CTVNews.ca.
“If you can see ordinary light through eclipse glasses or filters, then they’re not safe and put you at high risk of damaging your eyes.”
Buyers should check their solar filter or glasses for any damage and avoid using them if there are scratches or dents. People should not use binoculars or take photos using their phones or cameras without the special filters over the lenses, she adds.
Glasses for good cause
Five high school students from Oakville, Ont., teamed up to create the Monarch Butterfly Eclipse Project. The students sell CE- and ISO-certified solar eclipse glasses made of cardboard frames with a monarch butterfly design, with the cheapest being a five-pack for $24.95.
Ellen Lentine, 16, says their idea began in 2017 when they used welding shields to view the partial eclipse in Ontario because they couldn’t find eclipse glasses.
Taylor Denton, 16, says they have received around 200 orders a day since Christmas.
“It was quiet in the beginning before Christmastime, but then once people started hearing about the eclipse happening it became really busy,” Denton said in a video interview with CTVNews.ca.
Lentine says all of their net profit will go towards protecting the habitat and population health of the endangered monarch butterflies, which are major pollinators.
“We connected those two because the migrating path of the butterflies are mirroring the path of the solar eclipse,” she said in a video interview with CTVNews.ca.