Millions of people will have their eyes on the sky on October 14 for a solar eclipse, which will be visible across parts of the U.S., Canada, Mexico and parts of South America. Best viewing will be in Oregon, Nevada, Utah, New Mexico and Texas which sit in the path of annularity. People are often tempted to have a look at a solar eclipse without taking into consideration the risks involved. Not only can looking at a solar eclipse damage your eyes, it can also lead to long-term damage.

The greatest vision risk when trying to watch an eclipse is looking directly at the sun without proper protection. The sun's intense rays, even during an eclipse, can cause serious damage to your eyes,” said Dr. Scott Allison, OD, and vice president, Professional Services at MyEyeDr. “This damage occurs when people underestimate the sun, thinking that an eclipse blocks enough of its light for it to be safe to view. Solar radiation remains dangerous during an eclipse.”

According to Prevent Blindness, there are several signs of eye damage to watch out for, including:




Unlike a total eclipse, an annular eclipse leaves a ring of light around the sun. Source: NASA
 
• Loss of central vision (solar retinopathy)
• Distorted vision
• Altered color vision

“The rarity of these amazing celestial events serves as a reminder of the importance of bringing awareness and eye health education to the populations who might be at risk in the viewing path,” said Dr. Allison. “Unlike a solar eclipse where the moon passes between the earth and the sun, causing the sun's intense light to be temporarily blocked, a lunar eclipse occurs when the earth passes between the sun and the moon. During a lunar eclipse, the moon is in the earth's shadow, so there's no direct sunlight reaching your eyes. That's why there isn't a risk to your vision when watching a lunar eclipse.”

Both Dr. Allison and the Association of American Optometrists, agree that eclipse glasses should be ISO12312-2, which ensures you can safely watch the eclipse without harming your eyes. Do not use eclipse glasses that have scratches, as this will make them less effective. Binoculars and telescopes should also be fitted with filters to protect the eyes.

“Never use regular sunglasses to observe the sun,” Dr. Allison said. “Reputable sources, such as MyEyeDr., provide certified eclipse glasses. These glasses have special filters that protect your eyes from the sun's harmful rays during an eclipse.”



This table provides the time that the eclipse begins in a city in each state in the U.S. Source: NASA


 
Eyecare providers are encouraged to offer their patients educational resources to ensure they are viewing the eclipse safely. For example, MyEyeDr.’s Texas locations will host Solar Eclipse Viewing Open Houses on October 14 from 11:00 a.m. – 2:00 p.m. for community members to experience a unique opportunity to safely view the eclipse crossing Texas. Participants will receive a free pair of special solar eclipse glasses to view the event.

“We know how exciting these phenomena can be to witness and are thrilled to provide a safe and fun way for members of the community to view them,” said Dr. Artis Beatty, chief medical officer, MyEyeDr. “Educating the community about the importance of vision health and wellness is one of our guiding principles. Together with Prevent Blindness, we look forward to making a difference in the communities we serve, both nationally and locally.”

Unlike a lunar eclipse, the sun is never fully blocked by the moon. This leaves the eyes at risk for “eclipse blindness.” This can result in retinal burns or solar retinopathy, which can be permanent.

“After a few seconds, there will be an afterimage, like when looking directly at a camera flash, which can last for many minutes afterward,” said Karl Citek, OD, MS., Ph.D and professor of optometry at Pacific University. “After a few minutes, there will be solar retinopathy, in which the sun's rays that are focused on the retina, usually in the macula, which actually causes permanent damage and thus blindness on that part of the retina.

“Someone with even mild solar retinopathy can then have best corrected vision of no better than about 20/40—worse in more serious cases. Looking at the sun on the horizon at sunrise or sunset without special protection is fine; an eclipse is not the same thing, even if it seems that light level might be the same or less," Dr. Citek said.

The AOA has several recommendations to help ensure safe viewing of the solar eclipse.




The eclipse will be visible in parts of the U.S., Canada, Mexico and countries in South and Central America. Source: NASA
  
• Get the proper eyewear. Wear approved eyewear to view the eclipse. If you wear regular glasses, ensure you wear the eclipse glasses over top. Do not use your camera or cell phone to view the eclipse.

• Use the proper sun viewing technique. Do not look at the eclipse for a long period of time. Use the glasses to view the eclipse, then look away.

• Be aware of harmful solar exposure. Staring at the sun for any period of time can cause damage to the retina, also called solar retinopathy.

• Visit your eye doctor. If you experience any form of discomfort following viewing a solar eclipse, contact an optometrist immediately.

Dr. Allison recommends that eyecare providers remind their patients about the importance of getting any eye exam and how it can make viewing a solar eclipse more enjoyable.

“Getting a comprehensive eye exam is important for many reasons. The innovative technology we use at MyEyeDr. can help detect vision problems such as nearsightedness, farsightedness, astigmatism, and eye diseases like glaucoma, diabetic retinopathy and cataracts,” he said

“These conditions, if left untreated, can affect your ability to see clearly, not just during an eclipse but in everyday life as well. By addressing these issues through regular eye exams, you can ensure that you have the best possible vision and enjoy celestial events like eclipses without hindrance. Regular eye exams are a crucial part of maintaining good eye health and overall health and well-being,” Dr. Allison said.

Sky watchers will also be able to enjoy a total solar eclipse on April 8, 2024, with optimum viewing across the East Coast.

Facts About Our Solar System
Here are a few fun and informative facts about our solar system, according to NASA.

• Eclipses occur due to the special coincidence of the moon and the sun being the same angular size. The sun is 400 times wider than the moon, but it is also 400 times farther away, so they coincidentally appear to be the same size in our sky.

• Eclipses only occur if the moon is located within 0.5 degrees of the plane of the ecliptic, on a line that passes through the center of the Sun and the earth.





• Thales, c. 610 B.C., is credited with predicting a solar eclipse from knowledge of a previous eclipse and using the Saros cycle.

• The orbit of the moon is not stable. Because of tidal friction, the orbit of the moon is steadily growing larger, so that the angular size of the moon from the earth is shrinking.

• The positions of the sun and moon are known to better than 1 arc second accuracy. This means that on the earth, the location of the track of totality is probably known to be about (1.0/206265.0) x 2 x pi x 6400 km = 0.19 kilometers or a few hundred meters at the earth's equator.

• The longest duration for a total solar eclipse is about 7.5 minutes.

• A total solar eclipse is not noticeable until the sun is more than 90 percent covered by the moon. At 99 percent coverage, daytime lighting resembles local twilight.

• Eclipse shadows travel at 1,100 miles per hour at the equator and up to 5,000 miles per hour near the poles.