Eye doctors are going to be busy tomorrow.
If you checked out the solar eclipse and weren't wearing certified protective glasses (or even if you were), you might be wondering if your vision is ok.
Looking at the sun without adequate protection allows sunlight, including ultraviolet and near-infrared radiation, to penetrate the retina.
That can burn parts of the eye and create a toxic reaction that causes damage, which can lead to a condition eye doctors refer to as photic or solar retinopathy.
If you watched the eclipse in an unsafe way, damage may not be immediately apparent, since you can't feel burns on your retina.
Some people might start to notice changes to their vision within a few hours, though it's most likely that vision changes would become apparent by the next day, according to the American Academy of Ophthalmology (AAO).
Symptoms of solar retinopathy include poor vision, changes to vision including blurry or discoloured spots, pain, and especially a loss of vision in the centre of the eye.
A number of solar retinopathy patients report being unable to read because of the changes, which can be temporary or permanent.
Scott Olson/GettySome people Business Insider spoke with said their eyes felt strange immediately after viewing the eclipse even though they did wear protective glasses.
If your glasses were properly certified and didn't let in any light that was less bright than the sun, the discomfort may just be a temporary effect.
It could be caused by the rapidly changing levels of light exposure you encountered while repeatedly covering and uncovering your eyes to look at the crescent sun.
The fact that your eyes felt weird after watching the eclipse doesn't necessarily mean there's any permanent damage.
People who watched the eclipse for even a brief period of time without protection, however, are susceptible to damage.
President Trump briefly demonstrated what you were not supposed to do, and tech entrepreneur Elon Musk may have done the same, tweeting that he watched with "sunglasses."
Sunglasses don't provide adequate protection and could potentially increase the risk for eye damage, since the pupil opens up more widely to let light in, according to Dr. Tongalp Tezel, an expert on retinas at Columbia University Medical Center.
If you are experiencing vision changes or eye pain, call an eye doctor to schedule an appointment.
A good proportion of cases do resolve themselves over time, potentially within a day or even over a couple of weeks, according to an editorial in the journal JAMA Ophthalmology.
But if vision hasn't come back within six months, it's not likely to - and there is, unfortunately, no present treatment for solar retinopathy.
A doctor can examine your eye and see changes to the retina, which can take on the appearance of the crescent-shaped sun responsible for the damage. Without medical confirmation, it's hard to know whether something is really wrong and to whether it can be addressed.
"I always, always say if you notice something strange about your vision, see the eye doctor," Adriane Santa Croce, an ophthalmic sonographer at Scheie Eye Institute in Philadelphia, told Business Insider.
She added that "the concerns about vision following the eclipse may uncover unrelated eye problems that people may not have addressed otherwise," including changes in vision related to diabetes, cataracts, macular degeneration, or glaucoma.
Interestingly, Croce noted that this eclipse should provide doctors with a better understanding of how light can damage the eye, since some imaging technology used now didn't exist the last time many people watched an eclipse.
Regardless of how your eyes feel after the eclipse, the AAO recommends regular comprehensive vision exams, since a number of health conditions can be first spotted in the eye.
If for any reason - eclipse or not - you notice any pain or vision changes tomorrow, call a doctor to be safe.
This article was originally published by Business Insider.