While the glasses pictured here are SAFE, some models being sold are not. On August 21st an incredible sight will be visible across all of the USA as a total solar eclipse moves clear across the nation from South Carolina to Oregon. It will make it dark as night for a zone 70 miles wide. Houston will not be in that area of, 'totality", but nearly 70% of the sun should be covered by the moon. This will briefly dim the sky as if a cloud passed over, for a few minutes. The closest city to Houston reaching 100% eclipse is Kansas City. (If you can, make the drive!)
But when viewing the sun, there are some REAL safely issues. You should not use your normal sunglasses to look, even they're the extra-dark kind. If you view the sun for an extended time (let's say 15 minutes) without the needed protection, you could literally go blind. Solar eclipses are dangerous because the sun naturally looks dimmer while the moon passes in front of it, blocking visible light. Our brains have evolved with an impulse to, "turn away" from bright visible light, but we can't detect UV radiation. With the pain of staring at the sun gone with the moon eclipsing it, you might receive a blinding dose of UV and not even realize it. So don't mess around with this. Do it right.
Unfortunately, you can't just go out and buy the first pair of eclipse shades you see being sold at retailers around Houston. Some could be sub-par, not adequately blocking the UV rays, which might lead to serious problems.
Here's what to look for:
- Buy only certified glasses which meet, "ISO 12312-2 international standards. So far, only 5 manufactures have achieved this.
- SAFE BRANDS TO BUY: Rainbow Symphony, American Paper Optics, Thousand Oaks Optical, TSE 17, Baader Planetarium [Europe].
- When purchasing a pair, after confirming that they're safe, reject any glasses that have scratches on the lens (even small ones) or bent, dinged, wrinkled or folded lenses. Sometimes in the packing and shipping process these defects can occur. Unfortunately even a hairline scratch could let UV in, causing serious retinal damage or blindness, after extended solar viewing.
- Homemade filters are a no go! Doubling or tripling up sunglasses or their lenses doesn't work either.
If you have a pair from a previous eclipse event, toss them! Apparently, these things only last 3 years before the materials in the lens that make them safe, break down.
While it's more fun to look right at the sun, there are other safe ways to view the eclipse that don't require special lenses. Try the pinhole projection! You can get fancy and take a large cardboard sheet, then poke a small hole in it to project an image of the sun on the ground. You'll see the crescent clearly this way, when ordinarily it would show an illuminated circle. If you stand under a shade tree and look down at the ground, you'll often be able to see, "hundreds" of eclipses projected. You can also use your hand, but putting your back to the sun and hands together, making a hole between.