On Monday April 8, 2024 Southern Ontario will experience either a partial or total solar eclipse. Some school boards, including the Waterloo Catholic District School Board, are scheduling a PD day that day as the peak of the eclipse is at 3:18 pm, and the Waterloo Region District School Board has now decided to close schools for a remote learning eclipse day. So what will the partial eclipse look like in Waterloo Region?
If it is a sunny day, the point at which the moon covers 99.3% of the sun will be like a huge dark cloud obscuring most of the sun, making it look quite dark for a few minutes. If it is a cloudy or rainy day, we won’t notice much except a slightly darker period of time on an already dark day. Only the areas within the path of totality will get the really dramatic effect of almost night time with a drop in temperature and the stars coming out, as long as the weather is clear. The closest area to us with totality is Brantford and for those who want to see totality, it might be best to avoid the Niagara Region and stay between Brantford and Lake Erie. A full tank of gas and packing a picnic lunch is also recommended as gas stations and restaurants may be swamped.
Why the concern?
On a very cloudy day when the sun is totally obscured by clouds, there will be little safety concern. There will be nothing much to see if there is total cloud cover. On a sunny eclipse day, because it is so much more comfortable to gaze at the sun when it is partly obscured by the moon (and because human nature makes children do exactly what they have been told NOT to do) permanent solar damage to the central retina (called the macula) can occur. Damage from looking too long at the sun or at a laser on ANY day can cause permanent irreversible blurred vision. Imagine not being able to read the bottom line on the eye chart. Even slight solar damage can mean a permanent reduction in vision of a few lines of acuity (think 20/25 or 20/30, which is one or two lines up the chart from the bottom). This is bad enough, but the longer someone stares at the sun or certain lasers, the worse the permanent blur becomes. It can take hours to days for the damage to become apparent and there is no treatment available for solar retinopathy.
What should I do during a Solar Eclipse?
First of all, we should NEVER purposely gaze unprotected at the sun or lasers. However, we also don’t want to terrify parents or children to think that the odd accidental quick look at the sun during an eclipse or on any day will cause harm. So caution and education are in order.
Ideally, this is a great opportunity for a teaching moment for all of us about astronomy. On April 8 parents may want to safely supervise children and teens with proper use of eclipse glasses or by viewing it indirectly using another method (see my previous post).
How do I use Solar Eclipse glasses?
Eclipse glasses are only useful for directly viewing the sun for a few minutes at a time during a partial solar eclipse (which is what we will have in Waterloo region that day from about 2 pm until 4 pm). You cannot walk around in eclipse glasses as they are too dark. However, for a TOTAL solar eclipse (nearest point to Waterloo is Brantford), during the 1-3 minutes of TOTALITY, the eclipse glasses will have to be removed as they will be too dark to see anything until the moon starts moving past the sun again. Then we move back into partial eclipse, which lasts until the moon clears the path of the sun’s rays again. In Waterloo Region the partial eclipse starts at around 2pm, with maximum coverage at 3:18 and ending at about 4:30. Click here for a short video describing the process of putting solar eclipse glasses on.
Can I take a photo of the Solar Eclipse?
Honestly, don’t risk frying the sensor on your camera. Just like you can permanently damage your retina looking at an eclipse, your expensive camera can also sustain damage. There will be professional photographers with special filters taking photos on the day. So just use a homemade cereal box pinhole camera to throw the image onto the sidewalk, or proper eclipse glasses to enjoy the spectacle safely.
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If April 8 is a cloudy day there won’t be much to see, so this could be a total bust! However a total solar eclipse is an exciting astronomical phenomenon which won’t happen again in Southern Ontario until 2144. The last total eclipse in these parts was in Northern Ontario in 1979 and Southern Ontario in 1925! If you want to see the path of the eclipse and exact times at various locations, click here for a video about a safe, free app called TOTALITY. Our Ontario Association of Optometrists also has an information page about eclipse safety linked here. Eclipse glasses are sold out now at our office but might still be available at KW telescope or Play-A-Latte Cafe in Kitchener.
With hopeful anticipation of a sunny day, let’s all plan for safe eclipse viewing and a learning experience for all ages! We will not be seeing patients from 3-4 pm that day, but feel free to join us on the sidewalk outside the front door of our office. We will have some eclipse glasses to share and fun information for kids if you would like to drop by for our eclipse party!
