Eye safety tips for the solar eclipse

April 8, 2024, marks one of the rare total solar eclipse events visible in the United States. As the moon passes between the sun and the Earth, it will cast a shadow on Earth and block out the sun. 

According to NASA, Monday’s eclipse will be the last total solar eclipse visible from the contiguous U.S. for 20 years. Part of Western Kentucky is in the path of totality, where the sun will be completely blocked, and most of Kentucky will be able to view at least a partial eclipse.  You won’t want to miss this extraordinary astronomical event, but how can you view it safely?  

Is it safe to view a total solar eclipse?

It can be dangerous to view a solar eclipse without the proper eye protection. Ensure you only view the moon when the sun is completely covered during “totality” and it suddenly gets dark. If you are in a location with a total solar eclipse, during totality, you can view the sun without an approved solar filter. However, as soon as the sun becomes visible again, you should look away quickly and put your approved protective eyewear back on.

The process of the moon gradually covering the sun spans around an hour, so remember to keep your protective eyewear on whenever observing the sun before or after the full eclipse. If you are in a location with only a partial eclipse, it is not safe to view without eye protection at any point. 

What eyewear is recommended to view the eclipse?

NASA recommends protective eclipse glasses that are International Organization for Standardization (ISO) 12312-2 certified. This is the easiest and most cost-friendly eyewear option to view the total eclipse, and the certification should be clearly printed on the glasses/packaging. 

Another eyewear option to safely view the eclipse is shade number 14 welding lenses. Before using your solar eclipse glasses, inspect them for any scratches, tears, or wear and do not use them if they are damaged. It is important to understand that standard sunglasses, camera lenses, phone cameras, binoculars and telescopes are not safe filters to view the eclipse through. 

Another option is to use a pinhole projector. This is achieved by poking a small hole in a thick piece of paper or cardboard, and with your back to the eclipse, raise the paper so the paper faces the sun and aim the light at a second piece of paper. In this way you can safely observe the eclipse without looking at the sun at all. 

Remember, if you want to take photographs or video of the eclipse, standard camera lenses and phone cameras will not be able to take photos safely or well without taking further precautions.

For full guidance on good eclipse photography practices, see the American Astrological Society’s recommendations by clicking here.

Can an eclipse hurt your eyes?

Exposure to solar energy without proper filters can cause harm to the retina, the light-sensitive layer at the back of the eye that processes all visual information. 

Remember that it is not safe to view the sun using ordinary sunglasses, even during the parts of the eclipse where the sun is partially covered. Protect yourself and prevent serious eye injury or potentially irreversible blindness by only wearing approved solar eclipse lenses. Solar retinopathy is a serious condition that can occur without proper sun-viewing precautions. Symptoms may include headaches, light sensitivity, blurred or distorted vision, pain, and even permanent vision impairment. 

If you experience vision changes during or following the viewing of an eclipse, seek immediate care from an eye doctor, such as an ophthalmologist.

References 

1. NASA Eclipse FAQ (https://science.nasa.gov/eclipses/future-eclipses/eclipse-2024/faq/) 
2. Bressler, N. M., Kong, J., & Arévalo, J. F. (2024). Safe Viewing of Solar Eclipses. JAMA. 
3. American Astronomical Society (https://eclipse.aas.org/eye-safety) 
4. American Astronomical Society- how to shoot eclipse images and video (https://eclipse.aas.org/imaging-video/images-videos) 
5. American Society of Retina Specialists (https://www.asrs.org/patients/retinal-diseases/special-safety-edition-2024-great-american-eclipse)