"At the New York Eye and Ear Infirmary emergency facility, we have already seen dozens of patients with concerns ranging from headaches to subjective blurry vision," said Dr. Avnish Deobhakta, an ophthalmologist with the New York Eye and Ear Infirmary of Mount Sinai Hospital. "While most patients have not had any permanent issues, a few have been found to have some retinal changes, which will require monitoring.
"Sun exposure can cause damage to many structures in the eye," Deobhakta added. "While we normally focus on the retinal damage that can happen, in some cases, people can suffer from light sensitivity and pain due to corneal damage."
If you're feeling a little weird -- some people have posted on social media about having headaches and nausea -- after looking at the eclipse, it could be a sign of something else.
Changes in vision can often cause headache or nausea, said Dr. Angie Wen, also at Mount Sinai and specializing in cornea, cataract and refractive surgery.
"If you feel that your headaches and nausea are associated with visual changes, such as blurriness while reading, then it is certainly possible," Deobhakta said. "In addition, if you are experiencing light sensitivity, that could also be a sign that your eyes have been affected."
"If someone believes they had accidental exposure to the sun during an eclipse, they should immediately make an appointment with their doctor of optometry for a comprehensive eye exam to ensure there is no serious damage," said Dr. Christopher Quinn, president of the American Optometric Association
Though symptoms of eye damage aren't immediate, here are some to be aware of.
- Blurred vision that doesn't improve in one or both eyes, especially the central part of your visual field.
- Wavy or otherwise distorted vision
- Difficulty discriminating colors from each other
- Sensitivity to light
- Seeing "spots" or "holes" in your vision
"Sophisticated in-office diagnostic testing will need to be performed to determine if the retina has been damaged," said Dr. Jane Edmond, a pediatric ophthalmologist at Texas Children's Hospital.
Looking directly at the sun can cause solar retinopathy, retinal damage from exposure to solar radiation, she said.
"The portion of the retina that is burned is very tiny, called the fovea," Edmond said. "This part of the retina gives us our central visual acuity. When it is burned and damaged, the very center of our vision is darkened or blurred, with variable decrease in vision -- from around 20/20 to 20/40 to 20/60. It is more common in younger patients because they do not have cataracts like older patients, and cataracts can block some of the damaging rays."
Unfortunately, there are no known treatments for solar retinopathy, Edmond said.
Photokeratitis, or ultraviolet keratitis, can also occur after looking at a solar eclipse without protection. UV radiation from the sun temporarily damages the topmost layer of the cornea, called the epithelium. It's also known as snow blindness, as it can happen during sun exposure from highly reflective snow at high elevations.
"Photokeratitis is often called a 'sunburn of the eye' and can be painful," Quinn said. "Its symptoms include red eyes, a foreign body sensation or gritty feeling in the eyes, extreme sensitivity to light and excessive tearing."
"It is very painful and feels like a corneal abrasion or scratch on the eye," Edmond said. "It usually goes away in one or two days and does not lead to permanent vision loss."