Solar eclipse and the eyes: it’s not so complicated. From an Optometrist and a Dad

 

 

Watching the eclipse is not dangerous IF properly viewed.

 

  • Covering your eyes with your hands and looking through your fingers is NOT properly viewing.

 

  • Wearing Maui Jim, Ray Ban, or ANY other brand name sunglasses EVEN IF POLARIZED is NOT properly viewing.

 

  • Wearing gas station sunglasses is NOT properly viewing (for the eclipse or any other time, but I digress).

 

  • Putting your hand above your eyes at your brow to block the glare is NOT properly viewing.

 

  • Repeatedly observing the eclipse through your solar filter and then through no filter is NOT properly viewing.

 

  • Wearing shade 13 welders glasses MAY be safe according to NASA.gov but has not been verified by the American Astronomical Society like safe solar filters.

 

  • Viewing through a camera, telescope or binoculars without the appropriate filtering lenses is NOT properly viewing and in fact is more harmful to your eyes.

 

This is not a comprehensive list, but you get the idea. The ONLY way to properly and safely view the sun directly at any time including during a partial eclipse is with solar filter lenses  (remember, very few places will experience 100% totality and the Louisville area will have no time of 100% totality viewing). It is ok to leave your regular eyeglasses on as long as your solar glasses are OVER the regular glasses, NOT UNDER.

 

The principle is that simple, but real life isn’t. I wish it were that simple. I wish I never saw patients with metallic corneal foreign bodies because they always wore full coverage safety glasses. I wish I never saw patients with permanent vision loss from corneal ulcers because they replaced their contacts monthly as directed instead of “when they start to hurt”. I wish I never saw patients with advanced glaucoma leading to tunnel vision because they had a yearly eye exam instead of not having one for multiple years because they ‘could still read road signs.” I wish I wouldn’t have patients on Tuesday with a permanent blind spot in their central vision because they thought ‘the sun wasn’t very bright so it wouldn’t hurt my eyes.” I wish.

 

Valid concerns that will cause damage to the eyes (this is not an exhaustive list)

  • Children (of all ages, including adults acting like children) are very likely to, voluntarily or via peer pressure or dares, remove or look around their solar glasses thus exposing the naked eye to solar burns
  • Even children inside, presumably protected from the sun may find themselves lured to the window or just gazing out one from a distance looking directly at the sun as the illumination changes so drastically.
  • This is going to be the first time most children have seen anything as spectacular as this. It will be captivating but they are still kids and may get bored if viewing for long periods and become more likely to take off their glasses.
  • Nearly all solar glasses will not fit children properly and may expose the naked eye to solar viewing. This is one of my main concerns.
  • Maybe the most talked about concern is the use of non-ISO approved solar filters or solar filters that meet ISO criteria but have not been made by NASA approved manufacturers. Or in general, just getting defective solar filter glasses. I will address this below.

 

Counter thoughts (some valid, some not)

  • You can’t really get a “sunburn” in your eye  NOT VALID
  • “I am going to wear my approved solar filter glasses and only view the eclipse through them so I am fine.”  VALID
  • “I am going to wear my non-approved solar filter glasses because I can’t see anything but the sun and I am only going to observe for a short periods (1-2 minutes). AT YOUR OWN RISK DEPENDING ON HOW MUCH YOU TRUST THE MANUFACTURER
  • I don’t need solar filter glasses, I’m going to make a pinhole camera (completely VALID way to INDIRECTLY view the eclipse, but do not look directly at the eclipse with this!)
  • You could watch it on TV (the “Couch-potato theory”) VALID
  • “I’ve looked at the sun hundreds of times in my life, in fact, I can tell time by looking at the sun so I’ll be fine.” NOT VALID

 

My family got our solar glasses this week. Immediately my kids wanted to “play” with them. They thought it was so cool that they couldn’t see ANYTHING through them. They were running around, bumping into things. It was fun. I went in the other room for a few minutes and when I returned, my kids had made their way outside to see the only thing they could see through the glasses. What I found, is what I expected to find as soon as I knew they were outside, and what I should have discussed before ever letting them touch the solar filter glasses: they were testing how much different it looked with the glasses and without. Now, don’t be alarmed, as bright as the sun was that day, they couldn’t look at it for more than a second and didn’t do it repeatedly because it was hurting their eyes to squint. All four of them are a bunch of blue eyed blondies with sensitive eyes and they couldn’t take it long.

 

BUT the eclipse will be different. There won’t be the physiological instincts of pupil constriction, squinting, and brow furrowing to help block the visible sunlight and the harmful invisible UV and infrared light. In fact, there will be no warning at all that an excessive amount of harmful light will be entering your eyes because the retina has no pain receptors. With prolonged or repeated improper observation of the sun during the eclipse your retina will literally experience a thermal burn (like your skin can) leading to decreased visual acuity that may or may not be permanent, and almost certainly will leave a partial or complete blind spot in the central or near central part of your sight in each eye. Even more alarming to me is that we in the Louisville area are near the path of totality, but not in it so we will get a very impressive view of the eclipse but will have some amount of the sun visible during any range of viewing of the eclipse. Even with only 5% of the sun visible a solar burn is possible, if not more likely to occur because of the lack of awareness of the intensity of the invisible light. My fourth grader reminded me that it’s ok to view the sun during the total eclipse because it is completely blocked and she “saw a video about it at school”. I reminded her that even though everyone is talking about the “total eclipse”, in Louisville we will always have at least a small sliver of sun coming through around the moon.

 

My final thoughts and recommendations

 

Enjoy the eclipse! Wear solar filter glasses!

Be vigilant in managing your children while viewing the eclipse making sure they are using the glasses and only viewing for short periods. This is a prudent idea for adults also…give your eyes a break from the direct sun viewing.

 

When not looking at the eclipse, it’s safe to remove your solar filter glasses and enjoy your company and the environment the eclipse is creating around you. Even if you avoid a solar retinal burn, staring at anything too long will dry out your eyes from not blinking frequently enough. View the eclipse safely and periodically but don’t forget to enjoy the view of the world without eclipse glasses during the eclipse and note the changes around you.  As long as you are not looking at the sun your eyesight is safe to see your surroundings, just like any other day, but with much more magnificent sights.

 

I plan to keep my kids viewing periods to only a couple of minutes at a time so that they can be closely monitored with their solar filter glasses in place. If your children cannot be trusted to keep their solar filters in place or to not look at the sun without them, then PLEASE keep them from being able to see the eclipse, even if inside.

 

EDUCATE your children and anyone else with whom you are viewing about the dangers of improper viewing. Consider a way to block the light from coming in around poorly fitting solar filter glasses (I hear google is good for that or check out doitonadimeblog.com). DO not look directly at the sun during the eclipse or any other time without solar filter glasses for anything more than a glimpse.

 

“You shouldn’t be able to see anything through a safe solar filter except the sun itself or something comparably bright, such as the sun reflected in a mirror, a sunglint off shiny metal, the hot filament of an unfrosted incandescent light bulb, a bright halogen light bulb, a bright-white LED flashlight (including the one on your smartphone), or an arc-welder’s torch,” according to the American Astronomical Society’s website. ”

 

IF you can see ANYTHING other than what is listed above through the glasses you bought that claim to be solar filter glasses, DO NOT USE THEM.

 

Enjoy!

Dr. Matt Mooney, OD

 

Resources:  https://eclipse2017.nasa.gov/safety

DIY pinhole viewer: http://wwwcache.wral.com/asset/lifestyles/goaskmom/2017/08/16/16884386/diy_pinhole_viewer-DMID1-5bs6v7t9v.pdf