The official eclipse viewers are made of a special metallised foil or black polymer and have been tested for eye safety when viewing the Sun. They block the harmful infrared and ultraviolet light that we cannot see, but which can burn your eyes. To look directly at the Sun, it is important to use official eclipse viewers only.

Make sure that the viewer is not damaged and that there are no holes in the foil that you look through.

To avoid straining your eyes it is a good idea to look at the Sun for 10 seconds or so, then look away, rather than watching it continuously.

If you do not have eclipse viewers for everyone, share them around, as one should not look through them continuously.