From making travel arrangements to choosing the perfect viewing location, tens of millions of people across North America are preparing for the total solar eclipse Monday.
The celestial spectacle will pass through Canada, the United States and Mexico.
Residents of Hamilton, Niagara Region, Brantford, Brant County, Haldimand-Norfolk and some areas in Halton Region will be in the path of totality, an area where the moon will completely block the sun for a short period of time.
While there are many things to figure out, having the proper eye protection to look at the total solar eclipse is arguably the most important.
Without it, you could face some dire consequences.
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Looking at a solar eclipse without eye protection
According to NASA, it is not safe to look at the sun without specialized eye protection. It says the only exception is during the short total phase of a total solar eclipse, when the moon completely blocks the sun.
The primary concern with glancing skyward during the partial phases of the solar eclipse without the correct eye protection is solar retinopathy. This is a condition caused by exposure to the sun’s intense light.
The retina, the delicate tissue at the back of the eye responsible for vision, can be irreversibly damaged when subjected to the sun’s rays without adequate protection.
“Basically what happens is similar to using a magnifying glass in the sun to burn a hole in a piece of paper,” says Dr. Philip Hooper, associate professor of ophthalmology at Western University in London, Ont.
“There is too much energy focused on a very small part in the back of the eye called the fovea, the centre of the retina, and it damages the cells by a thermal effect, almost like cooking them.”
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This damage can manifest as blurred vision, blind spots or even permanent vision loss.
One of the insidious aspects of solar retinopathy is that the retina lacks pain receptors, meaning individuals may not immediately realize they’ve sustained damage.
If symptoms arise, Dr. Hooper recommends seeing a medical professional.
“Time and the body’s own healing effects really determine the outcome,” he says.
“The most important thing if you think you’ve had exposure is to get out of the light and not further challenge your eye, and seek medical attention.”
What glasses are safe for the solar eclipse
To safeguard against solar retinopathy and other eye injuries, experts advise eclipse viewers to use certified eclipse glasses or solar filters.
These filters block harmful ultraviolet and infrared radiation while allowing safe levels of visible light to pass through.
Dr. Hooper recommends people wear eclipse glasses that comply with the ISO 12312-2 international standard when viewing the solar eclipse.
“That indicates that they’ve been tested and provide the level of protection required. Anything else is taking a chance, and it’s not a good idea,” he says.
What’s not safe for viewing the solar eclipse? Regular sunglasses.
“They just don’t block out enough light. It’s a matter of many magnitudes less light that needs to get to your eyes when looking at the sun than in usual circumstances,” Dr. Hooper says.
Most southern Ontario events along the path of totality are expected to offer a limited number of free eclipse glasses.
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