Pilgrims at a renowned religious site in the west of Ireland have been warned that staring at the sun in the hope of seeing apparitions could seriously damage their eyesight.
Thousands of people flocked to pray at the Knock shrine in Co Mayo in October, where they claimed to see the sun shimmering and dancing in the sky.
But University College Hospital Galway said it has seen five cases of the damaging eye condition solar retinopathy this year, with four directly linked to people gazing at the sun.
Dr Eamonn O'Donoghue, consultant ophthalmologist surgeon at UCHG, said the hospital would normally see just one case a year on average.
"All of these people were under the impression they would see a strange phenomenon if they looked at the sun and it is associated with events at Knock," Dr O'Donoghue said.
"It is a shame to see Knock being misused this way."
Knock, where the Virgin Mary, St Joseph and St John the Evangelist are said to have appeared in August 1879, has been a place of pilgrimage ever since.
It is one of a series of sites in Ireland attracting hundreds of pilgrims over the last year in the hope of seeing an apparition.
Locals in Rathkeale village, Co Limerick, held prayer vigils in a churchyard after a tree was cut down and some people claimed to be able to see an image of the Virgin Mary on the stump.
Others have gathered at sites in Donegal and claimed to have seen holy statues weeping.
'Bizarre phenomena'
People suffering from solar retinopathy have had the tissue at centre of their retina, known as the macular, effectively burned.
"If you get a burn to the macular you are going to see bizarre phenomena," the doctor said.
"This is a tissue of very limited capacity for self-repair."
Normal vision could return after a few weeks for mild damage, but severe solar retinopathy will permanently damage a person's vision.
Thousands of people turned up at Knock on two occasions in October hoping to see a visitation from the Virgin Mary.
It had been predicted by Dublin man Joe Coleman, a self-proclaimed spiritual healer.
Mr Coleman, who has predicted another vision in Knock this Saturday, was not available for comment.
© Press Association