Eye Safety: Viewing the Solar Eclipse

Demonstration of incorrect vs. approved solar eclipse glasses
Solar eclipse glasses requirement
Dr. Ian Han demonstrating how to test your approved solar eclipse glasses
OCT (top) and infrared (bottom) images show laser maculopathy, which can look similar to solar retinopathy and has the same pathophysiology.
Ophthalmology staff safely viewing the solar eclipse on  August 21, 2017

2024 Solar Eclipse Map - NASA

A solar eclipse is set to grace the skies of the United States on Monday, April 8. During this event, the moon will pass in front of the sun, resulting in a brief but total solar eclipse while traveling over North America. The last time this phenomenon occurred over the contiguous United States was August 21, 2017, but prior to that such an event hadn't been seen since 1979.

Watching a solar eclipse can be an extraordinary experience but looking directly at the sun can seriously damage your eyes. Proper eye protection during the eclipse period is necessary to avoid damaging your vision permanently. 

Ian Han, portraitDr. Ian Han, ophthalmologist and retina specialist at the University of Iowa, is looking forward to the upcoming solar eclipse.

“Solar eclipses are really exciting. I think they’re a great educational event, and I’m looking forward to having a good viewing with my daughter as well, but if you’re going to view the eclipse we want you to do it safely.” 


Q. How do you keep yourself safe while viewing an eclipse? 

I think one common misconception is that you can just wear sunglasses or some sort of dark shades. The reality is that can still be really, really dangerous. You need approved glasses. You can get these at any reputable retailer, but specifically, there’s a type of glasses you need that says ISO 12312-2 (sometimes written as ISO 12312-2:2015). And these are really important to wear if you are going to look directly at the sun. If you try it indoors, you shouldn’t even really be able to see the outline of a bright light on your ceiling. It’s a good way to test in advance. 

Q. What can happen if you don’t take proper precautions when viewing an eclipse? 

There are a lot of conditions where bright light can actually cause a burn or some permanent damage to the back of the eye. Your eye has a lot of focusing mechanisms up front that direct it toward a light sensitive tissue in the back of the eye called the retina. And if you’re staring at an eclipse, or even just the sun for too long, the energy and light directed back there can cause some damage to the cells which can result in symptoms, including a blind spot that in some cases may be permanent. And the permanent blind spot might be in the worst part of your vision, smack dab in the center.

Q. What is solar retinopathy? What are the symptoms and when will damage be noticeable?  

Solar retinopathy is sometimes called eclipse retinopathy and is caused by direct sungazing, even for a few seconds. Doing so causes light-induced damage, as the intensity of the sunlight causes burns in the retina. Symptoms include decreased vision, including a central graying or a blind spot, decreased color vision, or distortion (straight lines looking warped). These symptoms are commonly in both eyes and are typically apparent soon after sungazing, though some patients may not be aware of the symptoms until a day or two afterward. Although mild cases may improve gradually over time, in more severe cases, some degree of central vision loss may be permanent.

Q. What are the treatments?

Unfortunately, there aren’t great treatments available for this condition we call solar retinopathy. Prevention is the key. You really want to be prepared with dark enough (and approved) glasses for safe viewing. 

Q. What should you do if you notice changes to your vision after viewing the eclipse?

First, you should call an eye doctor to be examined for this actual diagnosis. We have a lot of advanced technology in the clinic that can help diagnose some of the changes. For example, there are some advanced cameras that we can use to evaluate the structure and the anatomy of the retina in case you do suffer from solar retinopathy. Seeking care is important for an overall assessment of your eye health, and to give you some guidance on what to expect going forward as you heal.

Q. Are there other ways to view the eclipse safely? 

There are, even without glasses. Most of these are indirect viewing mechanisms, such as a classic pinhole set up. You can find various suggestions online, but it’s a really nice method for kids in particular. You can set up a little box, for example, with a little pinhole through it, and what’s nice is it casts a shadow of the eclipse onto the ground for you to view. These eclipses take a little bit of time, even if you happen to be in the path of totality, it lasts a few minutes, so the gradual movement of the eclipse can be viewed very nicely that way. 

Enjoy the eclipse and stay safe out there!

Additional Resources

Thursday, April 4, 2024