French President Jacques Chirac has been admitted to hospital suffering from an eye problem.
The president's engagements have been cancelled for a week
The 72-year-old will remain at the Val de Grace military hospital in the capital Paris for about a week.
The hospital said the president was being treated for "a minor vascular incident" that had slightly affected his eyesight.
Mr Chirac almost certainly suffered a blood clot lodged in his retinal artery, a leading cardiologist said.
Most patients recover from the incident - known as a transient ischemic attack - as the clot dissolves, said Piers Clifford.
"It is possible that the damage becomes permanent," the cardiologist added.
The condition is normally treated with anti-coagulant drugs.
French Prime Minister Dominique de Villepin told reporters he had visited the president in hospital and found him "in good form."
"Naturally, we discussed the agenda of the coming days, and in particular the offers of aid and assistance to our American friends faced with the terrible catastrophe that has struck the south of their country," he said.
Mr Chirac's office said all his engagements had been cancelled for the coming week.
French cardiologist Alain Ducardonnet told the TF1 television station it was vital that the president underwent a full arterial check-up "to avoid a more serious incident".
"This is without a doubt an alert in the brain region, in a small artery that feeds the retina," he added.
Mr Chirac has had a reputation for robust health throughout his political career and has suffered no major health problems.
The head of Mr Chirac's UMP party - his political rival Nicolas Sarkozy - said the whole party wished the president well.
German Chancellor Gerhard Schroeder has also sent Mr Chirac a "get-well-soon" message.