Watching an eclipse
You should never look directly at the sun. This applies when there’s a total or partial eclipse as well. This is because the radiation emitted by the sun is so powerful it may cause a solar burn of the retina.
How can I view the solar eclipse safely?
By following this advice, you’ll be able to enjoy this rare event without causing yourself unnecessary harm:
- Don’t look directly at the sun, even with sunglasses on – they don’t offer enough protection.
- Don’t watch it directly through a telescope, binoculars, camera or camera phone. Even if you are just lining up the projection, this still puts you at risk.
- Do use the pinhole projection method (see below).
- If you have to view the eclipse directly, use ‘eclipse glasses’ with specially designed solar filters (bearing the CE logo) You can buy ‘eclipse glasses’ easily from many outlets but do check the surface to ensure they are not scratched before use.
What is a pinhole projector?
A pinhole projector (see diagram above) involves putting a hole in a piece of card, and holding the card up with your back to the sun so that an image of the sun is projected onto another piece of paper or card. This will allow you to see the progress of the eclipse without damaging your eyes.
You will need:
- one piece of stiff card
- one sheet of white paper
- a drawing pin.
1. Make a small hole in the card using the pin and hold the card in front of the sun.
2. Hold the paper at a distance in front of the card – the sun will project through your pinhole on to the paper screen.
3. Adjust the distance between the card and paper to make the image of the sun larger but remember, your back should always face the sun and don’t look through the pinhole.
Are there other ways to watch the eclipse?
Watching a webcam or television broadcast is an easy and safe alternative to using a pinhole projector.
What if I accidentally look at the sun?
If you accidentally look at the sun during the solar eclipse and you have concerns about the health of your eyes, please contact your optometrist.