On Monday, August 21, 2017, parts of the United States will experience a total eclipse of the sun. Here in Ottawa, we won’t lose sight of the sun in its entirety, but we will experience a partial eclipse. It is important to take precautions to protect your eyes.
Even though it will be only a partial view, if you plan on taking a look, it is extremely important to take precautions to protect your eyes.
Why is it dangerous?
When the moon passes between the earth and the sun, the moon casts a shadow on the earth and the sun appears to darken. It is never safe to stare directly at the sun. Even though the sun may appear dark during the eclipse, if any part of the sun is visible, it is still extremely dangerous to stare directly at it. This means that, for the duration of the eclipse from 1:17 to 3:48 p.m., it will not be safe to observe the sun at all in Ottawa without protective eyewear.
Prolonged viewing of the sun without ISO-certified eyewear leads to a condition called solar retinopathy, which can cause reduced vision and even permanent vision loss in some patients. There is no real treatment for this, as it results from a destruction of retinal tissue. Once the retinal tissue is gone, we cannot get it back.
Children at particular risk
As an optometrist, I am especially worried about children, as they may not fully understand the importance of not looking directly at the sun when it appears darker. At our clinic, we recommend that young children be kept inside during the eclipse so they’re not tempted to stare up at the sun.
If you and your children are viewing the eclipse with protective eyewear or shields, make sure they keep their protective glasses on at all times. It can be difficult for a young child to keep the glasses on because, unlike their regular sunglasses, they won’t be able to see anything when they look through them. (When wearing protective eyewear, you should only be able to see the sun.) That can get boring for a young child, so parents and caregivers really need to be vigilant to make sure that kids aren’t removing or wiggling their glasses around.
The safest way for you and your family to view the eclipse is to watch it online or on TV, many news stations will be covering the event live. If you’re set on watching it live, then the next safest way to view it is indirectly with a pinhole device. Both NASA and the Canadian Space Agency have instructions on how to make a pinhole viewer.It’s a great art project to do with children who are old enough to understand the dangers. Another great option is to experience the eclipse by visiting the Canada Aviation and Space Museum, which will have a telescope set up with special filters.
If you have purchased eclipse glasses, make sure they were produced by a reputable source and are ISO-certified, and that you cannot see anything except the sun through the lenses. There has been large scale recalls of some glasses sold by Amazon as well as some glasses given out by hospitals and schools because they’ve been shown to carry a fake ISO stamp.
Don’t worry if you’re going to miss out on this eclipse; there’s another partial event coming up in Ottawa in June 2021, and an almost total (98%!) eclipse happening in April 2024.
Image of partial solar eclipse from Canadian Space Agency.