Don't Look Directly at the Sun During the Solar Eclipse

Experts warn that looking at the eclipse, even briefly, can cause permanent eye damage and vision loss.

On April 8, people in certain regions across the United States, Mexico, and Canada will have the rare opportunity to witness a total solar eclipse. During this rare celestial event, the moon completely covers the sun for a few moments, darkening the sky as if it were dawn or dusk.

Locations in the eclipse's path could become so dark that nocturnal animals may emerge from sleep thinking it's nightfall.

A total solar eclipse will not occur again until August 23, 2044, so many Americans are eager to catch a glimpse of this fascinating event. However, experts warn that if a person is not careful, viewing the partial phases of the eclipse occurring before and after totality can cause severe eye damage and vision loss.

How can looking at an eclipse damage eyes?

Looking directly at the sun at any time can cause damage to the retina, a layer of photosensitive tissue located on the back of the eyeball. Typically, people have no desire to stare directly at the sun because its intensity causes discomfort.

But during a total eclipse, people are more likely to engage in this dangerous activity because the eclipsed sun isn't as uncomfortable to look at, so they might believe it's safe.

However, even looking at a sliver of sunlight emerging around the moon during the eclipse can damage the retina. That's because the eye's lens is designed to focus light on the retina to enhance visual clarity. So, if a person looks at the sun even for a few seconds, its intense light can cause photochemical injury to the retinal tissue, resulting in permanent damage and vision loss.

Ophthalmologists call this condition solar retinopathy.

According to a study published in JAMA Ophthalmology, this retinal damage can appear in the exact shape of the sun's crescent peeking out behind the moon — revealing the precise moment a person looked directly at the eclipse.

Once the damage is done, there is no known treatment or cure.

Symptoms of solar eclipse eye damage

According to the American Academy of Ophthalmology, the retina has no pain-detecting nerves, so damage from looking at an eclipse will likely cause little, if any, discomfort.

However, a person with solar retinopathy may experience vision changes within four to six hours after sun exposure. These changes include:

• Blurry vision
• Headache
• Increased sensitivity to light
• A blind spot in the central vision in one or both eyes
• Distorted vision
• Dyschromatopsia, or changes in how a person sees color

An ophthalmologist can scan the eye to determine the extent of the damage. While some individuals recover after about three to six months, others will experience permanent vision loss characterized by a blind spot or distorted vision.

How to look at the solar eclipse safely

In a Mount Sinai news release, Avnish Deobhakta, M.D., Associate Professor of Ophthalmology at the New York Eye and Ear Infirmary of Mount Sinai, said people should be extra vigilant on April 8 and resist the urge to look up at the sun.

While some experts say it's safe to look at the eclipse wearing special ISO 12312-2 compliant glasses, Deobhakta advises against it.

"As a doctor, I would advise you to not use even the sunglasses that people say are safe," Deobhakta said. "You would really have to trust those glasses. Most of the people I've seen whose eyes were damaged by looking at a solar eclipse thought they were wearing the right glasses. And if you think you're protected, you're going to look longer, which increases the chance — and the extent — of damage."

Deobhakta also advises against viewing the eclipse using mirrors or phone cameras. While holding up a phone camera to record the eclipse might seem safe, people may accidentally look around their phones, and even a brief second of the sun's rays can cause damage.

Deobhakta suggests that the only safe way to view a solar eclipse is through a pinhole camera, which can be made at home using white card stock, tape, aluminum foil, and a pin.

"They reflect light off an object and onto a surface such as a cardboard box or a wall," Deobhakta explained. "That way you're not looking at the rays themselves, you're looking at a projection of what the rays look like. You can watch a pinhole camera image as long as you'd like; you can even watch the entire solar eclipse reproduced on a pinhole camera, and it's perfectly safe."