The only safe way to view the eclipse is by using a pinhole viewer, according to the Association of Optometrists in Ireland. The medical body has reiterated its warning that permanent eye damage can by caused by looking directly at the sun even with the aid of strong light filters or sunglasses.
A pinhole viewer should be used while one's back is facing the sun. Held over a shoulder, the light from the hole can be projected on to a plain white card, thus providing a view of the eclipse.
Safety warnings have also been issued by people who suffered eye damage from viewing previous eclipses directly.
David Berger-Jones (12), from North Carolina, is to publicise the dangers of eclipse watching in Cornwall next week after the sun's radiation burnt a hole in his retina. He said he felt no pain when he viewed a partial eclipse last year through several viewing devices, all of which were believed to be safe.