You may know that a total solar eclipse is coming our way on Monday, August 21. This is very exciting! The last time there was total solar eclipse was 40 years ago!
One misconception about an eclipse is that it’s safe to look at the sun, because it’s more comfortable to look at than a typical sunny day. But, if someone looks at the total eclipse and the sun even begins to peek back out, they could begin to put themselves in danger to seriously injure their eyes without proper sun protection. Even wearing sunglasses , which block harmful UV rays, do not make it safe to look directly at the sun with since they do not block harmful infrared or intense visible light that can cause damage from staring at direct sunlight.
Solar retinopathy occurs when bright light from the sun floods the retina and is caused by staring at the sun for too long. Most people can’t stand to look at the sun long enough to cause damage, but the eclipse (partial or total) makes it more comfortable to stare at the sun.The retina is home to the light-sensing cells that make vision possible. When they’re over-stimulated by sunlight, they release a flood of communication chemicals that can damage the retina. This damage is often painless, so people don’t realize they’re damaging their vision
Sunglasses block harmful UV rays, but not harmful infrared or intense visible light that can cause solar retinopathy from staring at direct sunlight. They are never safe for looking directly at the sun.
Photokeratitis is a painful eye condition that happens when your eyes are exposed to UV rays. It is like having sunburned eyes. This condition can be prevented by wearing eye protection that block UV radiation, such as Transitions lenses.
The only safe way to look directly at the sun is through glasses that meet the ISO 12312-2 international standard.
Only four manufacturers have met this standard: Rainbow Symphony, American Paper Optics, Thousand Oaks Optical and TSE 17. Solar eclipse glasses have met the following standards for becoming ISO certified: 100% harmful UV, 100% harmful infrared and, 99.99% of intense visible light. An alternative method for safe viewing of the partially eclipsed sun is pinhole projection. Visit https://eclipse2017.nasa.gov/safety for directions on this indirect viewing method.
Wondering where to view the eclipse in Toronto? Visit http://www.toronto.com/things-to-do/where-to-watch-the-solar-eclipse/