Staring at a partial eclipse will seriously affect your eyesight

Northwestern Health Unit - Special to The Bulletin

On April 8th, 2024, residents of northwestern Ontario will experience a partial solar eclipse and watching the event without special eye protection can do serious damage to your vision.
From approximately 1:00 pm – 3:30 pm CST people in the northwest will see the moon block a portion of the sun. During this time the solar radiation being emitted from the sun can cause ‘eclipse blindness’ or retinal burns. This eye injury is caused because tissues inside the eye are heated to an extreme level – all without feeling pain. Blurred vision and loss of eyesight (immediate or delayed) is also possible and can take 12 to 48 hours to appear.
Thomas Nabb, Environmental Health Manager, explains “only viewing glasses with the ISO 12312-2 international standard markings are acceptable. Sunglasses, cameras, telescopes and binoculars are simply not safe.”
Public health officials and the Canadian Association of Optometrists recommend viewing the event online or making an eclipse box which is essentially a pinhole projector. Instructions on how to make an eclipse box are easy to find on the internet. For more information, including info about suppliers of safe solar viewers and filters, visit the NWHU website (https://www.nwhu.on.ca/our-services/emergencies-and-being-prepared/solar-eclipse-safety/), or that of the Canadian Association of Optometrists (https://opto.ca/eye-health-library/solar-eclipse-safety).
Additional information

• A total solar eclipse is a rare celestial event where the moon passes between Earth and the Sun, casting a shadow on the Earth’s surface. This moving shadow, called “the path of totality”, will pass over many municipalities in Ontario.
• Glasses with specialized filters adhering to the ISO 12312-2 international standard can be worn to prevent eye damage.
• Glasses should be inspected for wrinkles or scratches ahead of use and should not be used if damaged.
• Ensure that eclipse glasses fully cover your field of vision.
• Put on glasses when looking away from the Sun, then look at the eclipse. Look away from the Sun before taking your glasses off.
• Children should always be supervised during eclipses as they may not fully comprehend the risks involved.
• If you begin to experience temporary visual loss, blurred vision, or eyesight loss during or after the event, speak to your eye care professional (e.g., optometrist) or your health care provider as soon as possible.
• If you are experiencing blindness after viewing the eclipse (immediate or delayed), seek emergency care immediately.