A total solar eclipse is coming to a state near you (including New York!). On April 8, 2024, areas in 15 states will be in the path of totality-when the moon completely blocks the sun. And while this means everything will go dark for a few minutes, it also means eye protection is paramount.
"During the eclipse, and any time you're out in the sun, it's important to have a plan to protect your eyes," says ophthalmologist Sonali Talsania, MD. "There is never a good or right time to look at the sun without proper protection."
We asked Talsania, who specializes in children's eye health, how to safely enjoy the solar eclipse and what happens if we do not.
What happens to our eyes when we look at the sun?
The sun's rays contain harmful ultraviolet (UV) and infrared (IR) rays that can damage our eye's retina and even cause blindness.
In the front of our eyes, there's a lens to focus light-just like a magnifying glass. So when we look directly at the sun, the very strong light rays get focused very powerfully inside the eye. This focus damages the retina: the part of the eye that actually makes the pictures we see.
Just like UV light can be too strong for our skin and damage it, it can be too strong for the retina if we look directly at the sun.
How much damage-and for how long-do we do to our eyes if we look at the sun?
Every second counts. The longer we look at the sun, the more damage is done to our eyes-just like sitting outside with a sunburn!
The damage to our eyes can be worse if we look at this sun through something else that magnifies it, like a camera lens or telescope that does not have a solar filter. This is especially important during a solar eclipse when you may be tempted to peek through these tools without protection. Do not do that. Always have eye protection.
What are the multicolor dots we see if we accidentally look at the sun? If you see spots, what should you do?
If we look at any light source (the sun or a lightbulb) even before there is eye damage, the part of our eye that absorbs the light and sees color can get temporarily used up. So, we then see the opposite color.
If dots or spots or anything unusual do not go away immediately (back to normal) and you are worried or you were looking directly at the sun, you should go to an ophthalmologist for a checkup.
How do you safely look at the sun?
It is never safe to look directly at the sun or its rays, even if the sun is partly obscured, like during an eclipse.
The only safe way to look directly at the sun is through specifically designed solar filters: solar eclipse glasses for direct viewing, and solar filters for telescopes and binoculars.
If you can see bright lights through your eclipse glasses or viewer, something is probably wrong. Stop using. You shouldn't be able to see anything through a properly made, safe, solar filter except the sun.
But eclipses are really cool! Can you wear sunglasses to look at the sun?
No. Not even very dark ones. Regular sunglasses are still much less dark than approved solar filters or viewers, also called solar eclipse glasses.
How long can you look at the sun while wearing eclipse glasses?
If you are using approved solar viewing glasses (per NASA, the ISO 12312-2 international safety standard) you can look at the sun for the entire time of the eclipse, every phase.
As long as the glasses are not damaged and compliant with safety standards, there is not a specific time limit.
What do all patients ask about the sun and their eyes?
How much sun exposure can my eyes have?
I usually recommend UV eyewear protection if you are planning to spend time doing outdoor activities for more than 15-20 minutes, especially if they involve water or snow, which reflect more sunlight.
References
Sonali D. Talsania, MD, is an Assistant Professor of Ophthalmology at the Vagelos College of Physicians and Surgeons.
