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Last Updated on Sunday, 02 May 2010 13:11
Published on Friday, 25 February 2005 00:00


A safety code drawn up by the Solar Eclipse 1999 UK Co-ordinating Group, mentioned in Dr Chou's statement below and supported by the Royal Astronomical Society, may be found on the following web site:

Contact details for Dr Chou, and a biographical note are at the end of his statement.

Statement regarding solar eclipse eye safety

Recently the Royal National Institute for the Blind (RNIB), UK Department of Health, and organizations representing the eye care professions of optometry and ophthalmology have issued advice advocating only the use of indirect viewing methods to observe the solar eclipse of 11 August 1999. Several of these organizations have actively discouraged the use of solar viewers that enable observers to look directly at the sun during the eclipse. It is disappointing to me that these organizations have chosen not to co-operate with the Solar Eclipse 1999 UK Co-ordinating Group in presenting an unbiased, common message on how to observe this spectacular natural event safely.

While the intention of these organizations is to ensure public safety during the eclipse, they have ignored the scientific evidence that solar viewers are safe when used as directed. Indeed, an examination of the scientific reports on eclipse eye injuries published since the 1960s shows that the principal causes of eclipse-related retinal burns are (in descending order): 1. Viewing the partly eclipsed sun without protection; 2. Looking through the pinhole of an indirect projection viewer (sunscope); 3. Viewing the sun through sunglasses, photographic neutral density filters, or other inappropriate devices.

There has never been a substantiated or anecdotal report of eclipse-related retinal injury arising from the use of a mylar solar viewer.

Messages that discourage an activity or behaviour, particularly when they are intended for young people, can backfire. This is especially so when the warnings turn out to be inaccurate or wrong. The advice issued by health authorities around the world on the subject of eclipse watching is a case in point. Unfortunately, many of these messages are designed to scare people from seeing the eclipse at all. When people heed these warnings and later learn that others saw the eclipse safely by disregarding that advice, they may feel cheated out of the experience. How then will they react in future to other health- related advice on drugs, alcohol, AIDS, and smoking from the same authorities?

Despite their good intentions, these organizations are doing the public a disservice by continuing to advocate this extremely conservative position on watching the solar eclipse.

B. Ralph Chou, MSc, OD
Associate Professor
School of Optometry, University of Waterloo
Waterloo, Ontario, Canada N2L 3G1
Tel: 519-888-4567x3741 Fax: 519-725-0784
e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Biographical note

Dr. B. Ralph Chou is Associate Professor of Optometry at the School of Optometry, University of Waterloo in Waterloo, Ontario, Canada. Dr. Chou's research is in the area of industrial and environmental eye protection with special interest in the analysis of, and protection from, optical radiation and impact hazards. He currently serves as Vice Chairman of the Technical Committee on Industrial Eye and Face Protection of the Canadian Standards Association, and as a member of the Eclipse Information Committee of International Astronomical Union Commission 46 (Teaching of Astronomy).

An amateur astronomer for 30 years, Dr. Chou has observed 12 total and 2 annular solar eclipses and led 8 eclipse expeditions. He has lectured on solar eclipse eye safety in the Philippines, Canada, the U.S.A., Romania and the Netherlands Antilles. He participated in eye safety campaigns for the total solar eclipses in Canada and the U.S.A. (1972, 1979, 1984, 1994), Mexico (1991), Papua New Guinea (1983), India and the South Pacific (1995) and the Caribbean (1998).

Issued by:
Dr Jacqueline Mitton, RAS Press Officer
Phone: Cambridge ((0)1223) 564914
FAX: Cambridge ((0)1223) 572892
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.