We’re getting the question pretty often here at Tigard Eyecare: ” How do I watch the eclipse?” Usually followed by “Are you selling the special eclipse glasses?”
To answer the glasses question: No, we currently do not sell any glasses that are appropriate for viewing the upcoming eclipse.
As for how to watch it, this page from NASA sums it up pretty well: Use special equipment that is made to view the eclipse and under no circumstances should you view it with your naked eye. Substantial and lifelong damage can occur to your vision if you watch the eclipse without special equipment.
Exposure of the retina to intense visible light causes damage to its light-sensitive rod and cone cells. The light triggers a series of complex chemical reactions within the cells which damages their ability to respond to a visual stimulus, and in extreme cases, can destroy them. The result is a loss of visual function which may be either temporary or permanent, depending on the severity of the damage. When a person looks repeatedly or for a long time at the Sun without proper protection for the eyes, this photochemical retinal damage may be accompanied by a thermal injury – the high level of visible and near-infrared radiation causes heating that literally cooks the exposed tissue. This thermal injury or photocoagulation destroys the rods and cones, creating a small blind area. The danger to vision is significant because photic retinal injuries occur without any feeling of pain (there are no pain receptors in the retina), and the visual effects do not occur for at least several hours after the damage is done [Pitts, 1993].
The only time that the Sun can be viewed safely with the naked eye is during a total eclipse, when the Moon completely covers the disk of the Sun. It is never safe to look at a partial or annular eclipse, or the partial phases of a total solar eclipse, without the proper equipment and techniques.