1. Looking at the eclipse without sunglasses?
On Monday, August 21, 2017, all of North America will be treated to an eclipse of the sun. Anyone who is within the path of the eclipse (which stretches from Lincoln Beach, Oregon to Charleston, South Carolina) will be able to witness this amazing event. Observers outside this path will still see a partial solar eclipse where the moon covers part of the sun.
Just in case you didn't know, you cannot look directly at the sun, even when it's covered by the moon, because you risk damaging your eyes.
2. What happens to your eyes when you look at a solar eclipse?
If your eyes are exposed to excessive amounts of UV (ultraviolet) radiation over a short period of time, such as during the eclipse, you could experience photokeratitis, essentially a sunburn of the eye.
Symptoms of photokeratitis:
- red eyes
- a foreign body sensation or gritty feeling in the eyes
- extreme sensitivity to light
- excessive tearing
- sensitivity to bright light
- seeing halos
- small pupils
- eyelid twitching
- rarely, temporary vision loss
How is photokeratitis diagnosed?
A doctor can diagnose photokeratitis by asking about your recent activities, examining yours eyes, and using an eye drop with fluorescein dye to look for UV damage.
Also, looking directly at the sun during a partial eclipse can also cause solar retinopathy, which can result in permanent damage to your eyes. This is caused by light from the sun flooding the retina on the back of the eyeball. This exposure to solar radiation on the retina causes damage to its light-sensitive rod and cone cells by igniting a series of complex chemical reactions within the cells.
Symptoms of Solar Retinopathy:
Symptoms commonly present within hours of exposure and include blurry vision and central or paracentral blind spot in one, or more commonly, both eyes. Additional complaints may include dyschromatopsia, metamorphopsia, micropsia, frontotemporal headache.
3. How long would you have to look at the sun to go blind?
Length of time doesn’t matter. Even looking directly at the sun for a short duration can actually burn the retina.
4. What is the best way to watch the eclipse?
The only safe way, and therefore the best way, to directly view the eclipsed or partially eclipsed sun [outside the 70-mile path] is through special-purpose solar filters or other ISO-certified filters, such as “eclipse glasses” or handheld solar viewers.
5. How long does photokeratitis last?
Most people experience mild photokeratitis, where your eyes will be red and in light pain for about one to two days. Severe cases include heavy pain in the eyes and lid spasms, and can actually last as long as six days, often requiring the sufferer to wear an eye patch during this time. Please see a doctor if you feel like you are suffering from photokeratitis.