Eclipse Viewing: Prioritizing Your Vision And Properly Protecting The Eye

Aug 11, 2017

The Great American Eclipse is a little more than a week away, and while you’re thinking about how you’ll be spending that time watching it, you should be more concerned about how you’ll be protecting your eyes from the rays of the sun. KRCU’s Lindsey Grojean spoke with Dr. Kyle Brost, senior optometrist at Brost and Associates, about the effects an eclipse could have on your eyes, and how to keep them safe.


So what do you recommend people do if they’re going to be watching the eclipse?


The total eclipse is going to take about 2 to 3 hours- the different phases of the eclipse itself. And during that period of time, the filters that you would want to wear are approved by the ISO  standards, and we have those at our office. We got them in about 5 or 6 weeks ago [and] they’re going like hotcakes, because people are very interested in this event that’s coming up on August 21. Those will allow you to view the sun during the eclipse, and assure that your eyes are safely protected.


What happens if you view the eclipse without protection? What happens to your eye?


What happens is that you can develop what we call photokeratitis - basically a burning sensation on the eye. The cornea in the front part of the eye becomes irritated. That’s the least of the ocular problems that can occur. By directly looking at the sunlight for any period of time, you can develop what is called solar retinopathy, which is basically a burning sensation in the back of the eye in the retinal tissue. And those changes start as chemical changes in the photoreceptors, the rods and cones in your eye. And with prolonged periods of viewing, a thermal condition can occur where basically you’re frying the center of your retina, and that will have consequences on your vision.


The preferred glasses that you should wear during the eclipse, what do those have in them to make them protect your eye?


Filters that are made have a coating that has aluminum chromium and a silver coating. So your regular sunglasses, or sunglasses that your mother got after her cataract surgery, are not going to protect the eyes. They have to have the special filter. A number 14 welding filter would be adequate also.


So how do people make sure that their glasses are certified?


Well, if you go to one of your eye care people in the area, they should be able to assess that. But they should have a stamp on there that says they are ISO approved for viewing the eclipse. There are five companies, I believe, that are approved to produce these, and they’ve been producing them for a long time, because the eclipse has been coming for awhile. I think Rainbow Optics is the one that we have used. The problem is, it’s late in the game now, and so, most of those are already sold, and the availability of those glasses is going to be limited at this time.


What about pinhole viewers? Do you know much about those?


You mean as far as indirect viewing? There are a number of places you can probably go online and check out how to form your own pinhole viewing system. Basically, it’s like a cardboard box and you put a little pinhole.. you don’t view the sun directly with it. You view an image of it against the backside of the cardboard box. But if you take a pinhole and look at the sun with it, all you’re going to do is direct those rays where you don’t want them inside your eye.


Is there anytime during the eclipse that people can look up at the sun, not AT the sun, but at the eclipse during?


That’s a great question. The only time that it’s okay for anybody to view the eclipse without a special lens is when the phase is in its totality. In other words, the moon is directly blocking the face of the sun, and all you can see is the corona of the sun around the moon’s image. That’s going to last in this area maybe 1 to 2 minutes. As soon as you start seeing the moon phasing out of that totality, you need to get the glasses back on.


If people do realize...


That they accidentally viewed that?


If they accidentally view the eclipse, what do they need to do? And what are the symptoms of a damaged eye?


So, there are no pain receptors in the retina that picks up the light. So you’re not necessarily going to feel any pain at all. That’s the bad thing. This can also occur immediately or it can occur several hours after you viewed the eclipse. But the things that you would notice would be a decrease in your vision. Basically, like I said, you’re frying the special cells that allow you to see. That will cause a reduction in vision. That reduction in vision could be temporary or it could be a permanent loss of vision. You’re not going to be able to grow new cells, no new photoreceptors. Reduction in color vision would be another thing, distortion of vision. Those would be the things that you’d want to be especially mindful of if you’re going to view the eclipse. Be wise, be smart. Don’t be cavalier. Don’t think that you’re going to be too tough to view this without any protection. You really need to use certified eclipse glasses and protect your eyes. You only have two eyes!