How to watch Thursday’s solar eclipse safely

Ophthalmologists said that the annular solar eclipse should not be viewed with the naked eye as it could cause retinal damage

An annular solar eclipse is seen formed over the sky of Male, Maldives, in January 2010

On Thursday, the annular solar eclipse will be visible in parts of the State. The annular eclipse known as ‘the ring of fire’ will be a rare spectacle, but ophthalmologists warn against viewing the phenomenon with the naked eye or take pictures using mobile phones or cameras. They also warn against viewing it through telescopes without sufficient protection.

Mohan Rajan, chairman of Rajan Eye Care Hospitals, says that though many goggles are being advertised online they are of indifferent quality. “The take-home message is do not view the solar eclipse. None of the filters are fool-proof. Even viewing it through a telescope is risky. You can watch it on television,” he says.

Unless specifically designed for the purpose, no filter is safe to use with any device, be they telescopes or binoculars. Ready-made eclipse viewers are available which may be used, he adds.

Viewing the solar eclipse could damage the eyes permanently. “It may take take a few days to realise the damage to the eye. The symptoms you can have are loss of central vision, distorted vision or altered colour vision,” Dr. Rajan says

Solar observations for more than 90 seconds exceed the threshold for retinal damage. Sunlight that reaches the earth contains sufficient amount of harmful ultraviolet rays to cause damage or even destroy the retinal cells.

“In any eclipse you must understand that you are not looking at the eclipse, but the sun’s rays. They are so powerful that they burn the retina of the eye. It is like heat going directly to the retina. There will be a black spot. Please don’t look at the eclipse directly. Even the reflection in a mirror is quite powerful,” said Amar Agarwal, chairman of Dr. Agarwal’s Group of hospitals.

Dr. Agarwal also cautioned against glasses available online: you may use these glasses, he said, but you cannot be sure of their quality. “Professionals use protective glasses. It is best to view the eclipse on the television. Those who are keen and enthusiasts, go to the planetarium where you could view the eclipse. You can, however, carry out your daily activities and even walk under the sun during the eclipse,” he said.