Vision problems after the eclipse? Here are symptoms of eye damage.

PHILADELPHIA — Millions of people were in the path of totality during Monday’s solar eclipse, where the moon completely blocked the sun. However, viewing the sun without properly made eclipse glasses can cause serious eye injuries, from temporary visual impairment to permanent blindness. According to NASA, even looking at the eclipse through the camera could cause serious eye damage.

According to NASA, the only time it is safe to view the sun without eye protection is during the totality of a total solar eclipse, or the brief period when the moon completely blocks light from the sun.

RELATED: Eclipse across US: Millions of Americans witness rare total solar eclipse

“The visible light, which would normally blind us, is temporarily not there. It’s blocked by the moon,” Dr. Joel Schuman, an ophthalmologist at Wills Eye Hospital in Philadelphia, told Action News before the eclipse. “So that allows us to stare at the sun without feeling like we’re actually taking damage.”

Now, in the wake of the solar eclipse, there may be an increase in the number of people wondering if they have caused any damage to their eyes by looking up without proper protection.

But how do you know if you have eye damage due to the eclipse?

While clouds hampered some viewing efforts in some parts of the U.S., many eventually caught a glimpse of at least the partial eclipse.

Before the eclipse, experts stressed that it was absolutely necessary to wear certified eclipse glasses or use portable solar viewers that met a specific safety standard, known as ISO 12312-2, when observing all other phases of a total or partial solar eclipse. . The safety standard means that the lenses meet international requirements for direct solar viewing, according to the American Astronomical Society, or AAS.

When asked what could happen if you don’t protect your eyes, Dr. Schuman said, “It would burn the part of your retina that has the most sensitive and sharp vision because you’re looking directly at the sun.”

The lenses of solar eclipse glasses are made of black polymer, or resin with carbon particles, which blocks almost all visible, infrared and ultraviolet light, according to The Planetary Society. And sunglasses don’t work in place of eclipse glasses or solar viewers.

While the highly specialized cells inside our eyes don’t feel any pain, the rods, cones and photochemical reactors become inflamed and damaged when looking at the sun, said Ronald Benner, an optometrist and president of the American Optometric Association.

It’s a bit like the effect that occurs when we see a camera flash going off, which can distort our vision for a few minutes before disappearing. But the intensity of solar retinopathy causes permanent damage that will not be evident immediately. Overnight, cells can die and will not be replaced. There is no treatment for solar retinopathy. It may get better or worse, but it is a permanent condition.

Changes in a person’s vision depend on the type of damage that occurs, and these can occur in one or both eyes.

“It can take someone a very short time, even seconds, to go from seeing 20/20 to seeing 20/200,” Dr. Schuman added.

“The retina is an extension of the brain, so it’s actually neurological tissue, and when it’s damaged, it doesn’t always come back,” Benner said. “If you damage one cell, that cell may never be the same. But if you damage a group of cells, you’ll end up with blurry vision, like someone rubbing oil on your windshield. If you just damage them and they don’t die completely, then color vision will be altered. What can you do about it? Absolutely nothing but prevent it.”

If the damage occurs in the center of someone’s vision, it can affect the ability to read or recognize faces, Benner said.

However, in the unlikely chance that you suffer more serious damage, you have likely already started experiencing symptoms, such as blurred vision, sensitivity to light, or dark spots.

If you experience vision problems or eye discomfort after viewing the eclipse, Benner recommends making an appointment immediately using the American Optometric Association’s doctor locator. Symptoms may take hours to a few days to appear and include loss of central vision, altered color vision, or distorted vision.

“For most people, it’s a color vision disturbance,” Benner said. “The next morning, the colors just don’t look right, or they may be washed out or just a little blurry all the time. For others, it may be that they actually have holes in their vision.”

Benner also said to talk to your kids.

“If your child has eye damage, they’re going to have to live with it for the rest of their life. And you may not be able to tell them, ‘I don’t see clearly out of one eye,'” he said.

If you have special glasses that helped you observe this rare celestial event, Here’s what you can do with them now that the eclipse is over.

Astronomers without borders has been accepting donations for over 15 years. They partner with organizations where you can drop off or send your used glasses.

You can also recycle them by removing the lenses and recycling the cardboard.

The next major total solar eclipse won’t return to North America for another 20 years (March 30, 2033) and will only include Alaska, with a partial solar eclipse over most of the country.

In the 2044 US eclipse, totality will only occur over North Dakota and Montana. Another with a broader path to the United States will occur in August 2045.

CNN contributed to this post.