Watch, but Watch Safely, During the Transit of VenusJune 5, 2012
On Tuesday, June 5, 2012, the planet Venus will pass directly between the earth and the sun. It will be visible as a small dot moving slowly across the face of the sun. Watching a solar event can be an exciting and educational experience, but people should do so safely, warns the American Optometric Association (AOA). Looking at the sun without proper protection can result in serious eye damage, the association says.
The entire event will be widely visible from the western Pacific, eastern Asia and eastern Australia. Most of North and Central America, and northern South America will witness the beginning of the transit (on June 5) but the Sun will set before the event ends (for its path, visit http://eclipse.gsfc.nasa.gov/OH/transit12.html).
However, the sun’s rays can burn the eye’s retina if a viewer looks directly at the transit without protection. The retina is the delicate lining at the back of the eye that contains layers of light-sensitive nerve cells used for seeing. Retinal burns cause a temporary or permanent vision loss based on the degree of exposure. Light-induced retinal injuries can occur without any feeling of pain and the effects of the injuries may not appear for at least several hours after the damage is done.
The AOA warns consumers to avoid viewing the event with the naked eye. Also unsafe are: sunglasses, color film, black and white film, medical x-ray films with images on them, smoked glass, photographic neutral density filters and polarizing filters.
The AOA recommends viewing with safer methods including the use of an image projection device, such as a pinhole projector (which can be constructed at home), or wearing a solar viewing filter to protect the eyes. Examples of safe solar viewing filters include shade number 14 welder’s glass (available from welding supply outlets) or glasses (available through special manufacturers) constructed specifically for solar observation.