Moments after Monday's solar eclipse began, searches on Google for "my eyes hurt" took off as thousands of eclipse watchers wondered if the warnings about possible eye damage were true.
Many people, it seems, including President Donald Trump for a brief moment, ignored the warnings about looking at the sun during the eclipse without protective lenses.
Interest in “solar eclipse eye damage” began to climb at 12:15 p.m. ET, around the time the shadow of the eclipse began to cross the country. By 1:20 p.m., interest in the topic had doubled, and about an hour-and-a-half later, at 2:56 p.m. it had quadrupled.
How would you know if you damaged your eye by looking at the sun during the eclipse? First, it will take a little while for the symptoms to show up.
Dr. Ralph Chou, a professor emeritus of optometry and vision science at the University of Waterloo, in Ontario, Canada, told NPR that it takes at least 12 hours before you can tell if damage has been done to the retina.
Chou is a leading authority on the damage the sun's rays can do to the eye's retina.
According to Chou, if you did not look at the sun directly, but instead look through a protective filter or at a display on your smartphone or a camera, you are likely OK.
If you looked briefly without protection – he described it as a “fraction of a second” – likewise, you should be fine.
However, if you looked directly at the eclipse for a period of time, you could have some problems.
Here are some symptoms of a damaged retina:
PreventBlindness.org says people with damaged retinas can experience sensitivity to light, burning eye pain or loss of vision or blurry vision.
You may also experience:
Loss of central vision
Distorted vision
Altered color vision
“This exposure to the light can cause damage or even destroy cells in the retina (the back of the eye) that transmit what you see to the brain,” according to the website.
“This damage can be temporary or permanent and occurs with no pain. It can take a few hours to a few days after viewing the solar eclipse to realize the damage that has occurred.”