Even for those of us whose geographical location will prevent us from witnessing much of the historic transit of Venus Tuesday evening, the once-in-a-lifetime event is exciting.
But for those who actually plan to watch the planet Venus take its last journey across the sun’s face until 2117, it’s really important to make sure you’ve got proper eye protection.
Staring at the sun any time can damage your retina, the light-sensitive layer of nerves at the back of your eye. Specifically, the sun’s radiation can harm the macula, the part of the retina involved in fine central vision, according to the American Academy of Ophthalmology (AAO). Children’s eyes are particularly vulnerable, as the lenses of their eyes are so clear, they don’t block much of the radiation.
Most of us aren’t inclined to stare at the sun on a normal day. But many will be tempted to do so in hopes of catching a glimpse of Venus in transit. It’s not safe to do so on a normal day, and it’s not safe to do so Tuesday evening.
Plain old sunglasses don’t offer sufficient protection, according to the AAO’s safe-viewing advice. NASA also offers safe-viewing tips, which include special guidelines about viewing through welder’s glass: “It is imperative that the welding hood houses a #14 or darker filter,” the NASA site cautions.
If you don’t happen to have your welding mask lying around, the AAO says, your best bets are:
A. to go to a planetarium or university observatory, where images of the transit will be projected for safe viewing
B. watch the event on TV or on NASA’s live-streaming Web site, or
C. make yourself a pinhole camera.
Happy — and safe — Venus viewing!