Keeping Your Eyes Safe During the Eclipse

Enjoy the Total Solar Eclipse with Eye Safety by Following These 4 Tips:

1. Always wear your ISO 12312-2 solar eclipse glasses during the eclipse to preserve your vision and keep the retina in each eye healthy and to avoid solar retinopathy.

2. Put the glasses on looking away from the sun and make sure the glasses fit your face and cover your eyes properly before you look at the sun.

3. Never use cameras, telescopes, or binoculars without their own solar filter, even when using solar viewing glasses.

4. Serve as a good role model and help others around you view the eclipse safely, especially kids.

Our eyes are our body’s camera. Light comes into the eye through the cornea and enters the back part of the eye through our eye’s natural aperture or opening, called the pupil, and reaches the retina. The retina is the back lining of the inner wall of the eye that is a complex network of cells and nerve tissue. The retina processes visible light rays or wavelengths into electrochemical signals that the optic nerve takes to the visual processing areas of the brain where images of what you see are formed.

The retina is very sensitive and delicate, like a wet piece of tissue paper, and is constantly active when we are awake and processing light. The cornea and lens focus light on the retina and the pupil constricts and dilates, depending on how much light is reaching the eye. This allows it to regulate how much light is reaching the retina to protect it from being damaged by exposure to too much light.

We should remember, that the rays of the sun reaching the eye not only contain wavelengths in the visible light range – causing us to see colors, but also have wavelengths that are invisible to the eyes. This includes ultraviolet or UV light and infrared light that can damage the retina if the intensity or duration of such light overwhelms the usual defenses in the retina against the effects of these wavelengths of light.

During an eclipse, the overall brightness of the sun is reduced when the moon blocks sunlight over a region of the earth. The darkness during the phases of the eclipse when the sun is partially covered by the moon causes the eye not to blink as much due to the decreased intensity of visible light, causing the pupil to dilate rather than constrict, which allows more visible as well as damaging UV and infrared light into an unprotected eye, over a longer period of time.

Even just a few seconds of this additional UV and infrared light entering the eye, overwhelms the ability of the retina to protect against their oxidative and thermal effects. This causes photochemical toxicity and damage to cells in the retina, called solar retinopathy. This damage may not appear for hours after viewing the sun and occurs without pain as the retina has no pain receptors.

https://eyewiki.aao.org/Solar_Retinopathy - Photos from the American Society of Retinal Specialists

While your body may be able to heal some of these damages, it can take over 3–6 months, and you may have permanent damage in the center of the retina which is responsible for your sharpest vision used in reading, seeing faces, and driving. You may also experience lasting and untreatable vision loss, blurry vision, missing pieces of vision, distortion of vision, and poor color vision, for which there is no cure.

Always use ISO 12312-2 certified glasses to protect your eyes. Do not use sunglasses. Put solar viewing glasses on while looking away from the sun and make sure they are not damaged and fit well. Also, make sure those you are helping to look at the eclipse, such as children and older adults, wear the glasses appropriately so that they fit well around the face and over regular glasses as needed. Both older adults with retinal diseases such as macular degeneration and children are more at risk of having retinal damage from unprotected viewing of the sun, including during an eclipse.

Do not use solar glasses or viewers as solar filters for cameras/telescopes/binoculars, they require special filters to block harmful rays from the sun from entering these devices. The sun's rays can burn the retina if a filter is not used, as these devices concentrate or focus light into a more powerful beam that can even burn through ISO 12312-2 compliant solar view glasses.

You can look through the eyepieces of properly filtered (ISO 12312-2) cameras, telescopes, and binoculars while making sure that the filter is in front of the lens closest to the sun, without solar viewing glasses.

The Rochester region is very fortunate to be in the path of totality when the entire sun is covered by the shadow of the moon and the only visible feature is the corona or outer atmosphere of the sun. During this brief time that lasts just over 2–3 minutes in our region, you will not see the sun through your solar viewing glasses. As there are no visible, UV or infrared light rays coming from the sun, it technically is ‘safe’ for your eyes to look towards the sun without solar viewing glasses, but extreme caution is needed as totality is very brief, and you should have your solar viewing glasses close to your eyes to immediately cover your eyes when totality ends.

I know many people will try to record sun during the eclipse with their tablets and phones. Do not however put the phone or tablet in between your eyes and sun without first wearing eclipse glasses. Camera lenses in these devices need special filters as prolonged sunlight can damage the sensors in these devices and there are special techniques for using these devices to take images and videos of the eclipse outlines on the NASA eclipse focused webpages.

You can also use indirect viewing techniques that are safe for the eyes, such as using a colander to project the sun that stays behind the person holding the colander or a pinhole viewer on a white sheet of paper to view the moon’s shadow gradually covering the sun.

Zachary Laird | 4/5/2024

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