How many people blinded by eclipse

This does happen, but not until at least three months after the injury. People have hurt their eyes by watching the sun during a solar eclipse unfiltered.

However, it is a relatively rare occurrence. Although Chou said there is no definitive data on the number of people afflicted with eclipse blindness, he noted that after a solar eclipse crossed Britain in , ophthalmologists reported 70 instances of eye injuries, and the majority of those people had viewed the eclipse unfiltered.

In Canada, 20 cases were reported following the total solar eclipse of Of the cases reported over the years, Chou said half the people afflicted completely recovered their vision over the course of the following year. Additionally, make sure that the brand of glasses you buy has been verified to meet the international safety standard, something Chou emphasized as critical to injury prevention. Good job people. Chou wrote in an email earlier today. But was anyone actually permanently affected, aka blinded by the eclipse?

In a case study , scientists and optometrists assessed visual symptoms that arose from solar viewing and found that there were 70 reported cases of visual loss that happened within two days of the eclipse.

The silver lining here though was that there were no reported cases of continued visual loss or blindness visual symptoms six months after the study was conducted. A total solar eclipse is when the moon completely blocks the sun.

A partial solar eclipse is when the moon only blocks part of the sun. 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. 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. If you notice symptoms after viewing a solar eclipse, seek treatment from an eye care professional. The only time that you can safely view a solar eclipse without special equipment is during a total solar eclipse. This is when the moon completely covers the sun.

It is never safe to look at a partial solar eclipse without proper safety equipment or techniques. During the very brief time the sun is in total solar eclipse it is safe to look at it, but do so with caution. Even during the total solar eclipse, the total eclipse may last only a short period of time, and if you are looking towards the sun as the moon moves away from blocking the sun, you might get a solar burn on your retina which can cause permanent damage to your eyes.

Talk with your eye care professional to determine the best viewing option for you. Below are a few common ways to safely watch a solar eclipse:.

Whenever someone stares at the sun, light from the sun hits the eye and focuses at the machinery called the fovea, which is located at the back of the eye. The light-sensitive cells that provide detailed color daylight vision , such as the cone cells , absorb light via photoreceptors and then translate that signal into an electrical impulse that is sent to the brain and perceived as a visual signal, Chou said.

But during a solar eclipse, "there's so much light hitting those cells that it actually disrupts the parts of the light-sensitive cells that are responsible for that transduction into a nervous signal," Chou said.

If the metabolic activity of those cones is disrupted significantly enough, the cells will stop functioning. Enough damage, and the cells will die. Those who have been staring particularly long at the sun through a telescope or other optical aid may even experience thermal damage, where they are literally overheating or cooking the eye cells, which causes those cells to die. Some people have even sustained crescent-shaped burns in their eyes, which mimics the shape of the solar eclipse.

People who sustain thermal damage have exposed their bodies to the same physical phenomenon that occurs when kids use a magnifying glass to focus light to burn grass or ants, Chou said.

One difference is that infrared light doesn't play a role in solar-eclipse injuries, as it does in heating via magnifying glass, he said. Viewing the sun during a solar eclipse without eye protection, but not through a telescope, will result in a smaller retina temperature rise, the researchers noted. People who sustain eye damage from staring at the sun may have difficulty seeing details, though they may have no awareness of the injury until a day later.