Safely Watch the Solar Eclipse


Guest Blogger: Shlomit Schaal, MD, PhD, Professor and Chair, Department of Ophthalmology and Visual Sciences, UMass Memorial Eye Center

The eclipse is coming. The eclipse is coming.

On Monday, August 21, a total solar eclipse will be visible in the certain areas of the United States for the first time since 1979. It’s been almost 40 years since we’ve been able to see an eclipse here in Massachusetts. Be sure to watch it safely.

While many will want to see this celestial phenomenon, NASA is warning that the only safe way to watch it is with special solar viewing glasses — also called eclipse glasses — or handheld viewers.

Within the last month, fake eclipse sunglasses have been flooding the market and can actually cause harm. Disreputable sellers are unlawfully copying the ISO label and applying it to untested products that are being sold on the internet and even in local stores.

There are several manufacturers such as American Paper Optics (APO), Rainbow Symphony, Celestron, Seymour Solar and Baader Planetarium, who make safe eclipse glasses and handheld solar viewers. Their products will all be labeled with “ISO 12123-2.” The lenses should have a metallic coating on one side and will be thousands of times darker than regular sunglasses. The American Astronomical Society has a list of reputable vendors for eclipse glasses and viewers. They do note that some legitimate products may not be listed if they have not yet been tested.

Here is where you can find a list of reputable vendors and retail stores. There are many unsafe glasses and filters that will actually cause damage rather than protect your eyes. If you do purchase eclipse glasses, inspect them for any scratches, pinholes or wrinkles which could let in the full sun rays in a very pointed way.

In Massachusetts, there will be a partial eclipse where only 63 to 65 percent of the sun is covered by the moon making proper eye protection even more necessary. No phase of this partial eclipse is safe to observe with the naked eye. The total eclipse is going to be seen only in 14 states during particular times. Here is where you can find the times and locations for totality. The full solar eclipse will only be visible in a 70-mile wide corridor that stretches from Oregon to South Carolina and will only be for two minutes.

Unsafe filters include everyday sunglasses, smoked glass, neutral density filters, polarizing filters and solar filters sold with inexpensive telescopes. It’s also not safe to view the eclipsed sun through an unfiltered camera, telescope, binoculars or other optical devices even when wearing eclipse glasses.

Unprotected and prolonged exposure to ultraviolet light from sunlight, lasers and arc welding leads to outer retinal damage – solar retinopathy – also known as eclipse blindness.

While most cases of eclipse blindness can recover fully, there is a significant percentage of patients that will suffer from reduced high-acuity vision and may sustain lifelong partial blind spots.

As we age, the crystalline lens yellows and provides more ultra-violet protection. In children, the crystalline lens is completely clear, making it much more dangerous for children to look at the sun or have a laser shined into their eyes.

But, when it comes to our vision, we definitely want to be safe rather than sorry. Prevention of sun damage to the eye is key. Please protect yourself and your children. Enjoy the great American eclipse and be safe. Dr. Schaal answers your questions about safely viewing the solar eclipse on Facebook Live.

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