This Friday, March 20th, there will be a total eclipse of the sun, and a partial eclipse will be visible in Spain from 9am-11am. This fantastic astronomical phenomenon is rare and should not be missed, but viewing an eclipse can cause permanent damage, even blindness. Children particularly must be protected from staring directly at the sun during the eclipse.
Specsavers Opticas offers the following advice for viewing the eclipse safely –
At Specsavers we agree with the RNIB, the Royal College of Ophthalmologists, the College of Optometrists and the Association of Optometrists that direct viewing of the sun during an eclipse is hazardous. We suggest using indirect ways of viewing the eclipse.
If you have a telescope or binoculars, you can focus an image of the sun on to a white screen, or hold white card behind the eye piece, adjusting the focus so you can see the image on the card. An inexpensive alternative is to create a pinhole camera using a piece of card with a pinhole in it to focus the image of the sun on to a white screen or piece of white card. However please always take care to shield the eyes from the sun.
If you want to make a pinhole camera, all you need is two pieces of plain card. Make a small hole (not more than 1mm wide) into one of the pieces of card. Stand with your back to the sun arranging the cards so that the one with the hole is close to your shoulder, with the other card 1 meter away. This will cast an upside down image of the sun onto the piece of paper and you can safely watch the eclipse.
It is very important to note that sunglasses, smoked glass, sun capes, solar filters and visors are not safe ways to view the eclipse, so please take care of your eyes and only view it indirectly.