How to Protect Your Eyes During a Solar Eclipse

On 21st August, the earth will experience a solar eclipse! This exciting celestial event occurs rarely and happens when the moon and the Sun line up. The result is the moon appearing to block the sun. In ancient times it was considered one of the worst of omens and the herald of the end times. But today, we know that the only worry is what will happen to your eyes if you stare at it!

A reminder: DO NOT LOOK DIRECTLY AT THE SUN

Why Shouldn’t You Look Directly at a Solar Eclipse?

You shouldn’t look at a solar eclipse because the UV rays from the Sun will damage your retina. When the Sun emerges from behind the moon, it can cause literal sun burn to your retinas. The sheer power of the Sun’s rays is too much for the human eye to handle directly.
Eclipses are exciting and impressive to behold, but you must take care. Every year, people are injured by looking directly at an eclipse. In one study, conducted in 1999 after a solar eclipse visible in Europe, 45 patients with solar retinopathy showed up at an eye clinic in Leicester in the United Kingdom after viewing the eclipse. Forty were confirmed to have some sort of damage or symptoms; five of those had visible changes in their retina.
Twenty of the patients reported eye pain, while another 20 reported problems with vision. Of the latter group, 12 reported that their sight had returned to normal seven months later, but four could still see the ghosts of the damage in their visual field, such as a crescent-shaped spot visible in dim light.

How to Look at a Solar Eclipse Without Damaging Your Eyes

There are several ways to enjoy an eclipse.

Build a pinhole projector

You will need:

• A long cardboard box
• a sheet of white paper
• aluminium foil
• a craft knife
• scissors
• a drawing pin
• duct tape
• glue

What to Do:

1. Cut a rectangular hole at the end of the box. You can tape 2 boxes together to make a long box. The longer the box, the larger the projected image.
2. Using the scissors, cut out a piece of the aluminum foil slightly larger than the rectangular hole. Make sure the foil is completely flat and not crinkled.
3. Tape the foil over the rectangular hole in the box.
4. Use the pin to poke a tiny hole in the center of the foil.
5. Tape the sheet of paper on the inside of the other end of the box.
6. Stand with your back toward the Sun. Place the box over your head with the pinhole towards the Sun. Adjust your position until you see a small projection, a negative image, of the eclipsed Sun on the paper inside the box.

What will you see?

A bright beam of sunlight will project onto the paper at the far end of the box. This is the Sun. When an eclipse occurs you’ll see an image of the Moon’s disc sweeping across your projection. The size of the image will be about one hundredth of the length of the box – so the longer the box, the bigger the projected image.

Wear protective lenses

Watching an eclipse directly is possible,  but it’s vital to protect your eyes with protective lenses. Never look at the Sun unless you are wearing a pair of special eclipse glasses. These cost a few pounds each and will block out more than 99.9% of the Sun’s light.

Test their condition by putting them on as you’re looking away from the Sun. You shouldn’t be able to see anything. If any light is entering through the glasses, this could mean that they are scratched and won’t provide adequate protection. When you’re satisfied the glasses aren’t damaged, turn to look at the Sun. This should be the only thing you can see – a big, orange globe surrounded by a black sky.