– On Monday, August 21, 2017, a total solar eclipse will span the United States. The moon will cover at least part of the sun for 2 to 3 hours, with some areas experiencing totality (or complete blockage) for up to 2 minutes 40 seconds. The 2017 Great American Eclipse is noteworthy for its path that makes it visible from most Americans' backyards; 500 million people across North America will see at least a partial eclipse, yet only about 12 million live within the “path of a totality”. That means it's especially important for Americans to clearly understand how to safely view the eclipse depending on their location.
“Looking at the sun, even for a short period, without proper protection can cause irreparable eye damage, even permanent eye vision loss,” advises Dr. David P. Nelson, Madison area optometrist and current President of the Wisconsin Optometric Association (WOA). “Since Wisconsin is not an area that will experience complete coverage, wearing glasses specifically designed for eclipse viewing is critical.”
Standard sunglasses, regardless of ultraviolet markings, including UVA and UVB, will not provide enough protection for eclipse viewing due to the intensity of the rays. The sun's rays may be partially blocked during an eclipse, but the remaining visible rays are still intense enough to cause serious eye damage or even loss of vision. “Eclipse glasses” should have an ISO 12312-2 marking on them to be considered safe for looking at the sun. These glasses should be closely inspected prior to use to ensure the solar filters are free of any scratches or damages. If imperfections are found, the glasses should be discarded. Binoculars, cameras and telescopes should not be used when viewing the eclipse, even if wearing eclipse glasses during use, as these devices can magnify the sun’s rays and negate the effectiveness of the protective eyewear.
“Children should be closely monitored during the eclipse,” explains Dr. Nelson. “Unlike the mature lens found in an adult eye, a child’s lens cannot filter out UV rays as easily, causing damage to the child’s retina. When children play outside, they are often excited and may remove their glasses or their glasses may fall off during activities.”
Overexposure to the sun rays can cause damage to both the front surface of the eye (photokeratitis) and the inside or back of the eye (solar retinopathy). Symptoms include eye pain, burning or red eyes, light sensitivity, blurred vision, difficulty in recognizing shapes, objects' appearing distorted, headaches, watery eyes, and/or swelling around the eye or eyelid.
"If experiencing any post-exposure symptoms, medical attention should be sought immediately, especially if the condition is worsening with time," says Dr. Nelson. "Just as with a sunburn, delayed symptoms can also occur several hours after overexposure."
The best way to monitor eye health, maintain good vision, and keep up-to-date on the latest in developments in vision protection is by scheduling yearly comprehensive eye exams for you and your family with your local optometrist.