Meteorologists have warned the people against watching the sun directly with the naked eye on Tuesday, June 8, as it can cause permanent blindness, within seconds.
"All observations which involve looking at the sun are also dangerous, and precautions must be taken to avoid permanent eye damage," they said and added: "Never observe the sun directly through a telescope, or binoculars, without proper optical filters fitted, to protect your eyes."
A 'Transit of Venus' will be observed in different countries, including Pakistan, on Tuesday from 10.14 am. to 4.27 pm Pakistan Standard Time, they said.
"When Venus comes directly between the Sun and the Earth, it will be seen to move across the bright solar disc," the meteorologists explained.
Venus, viewed from the Earth, will appear as a black dot moving slowly from West to East across the southern-most part of the Sun's bright disc with a diameter of approximately 12403 km.
Only six such events have occurred since the invention of telescope (in 1631, 1639, 1761, 1769, 1874 and 1682) and the next two transits will occur on June 8, 2004 and June 6, 2012, they said.
On June 8, half of the globe, including Europe, Africa, Asia and eastern parts of America will be able to watch this tiny black dot of the Venus planet.
The transitional period of black dot across the Sun on Tuesday will start at 10.14 am at position angle of 116.3 degrees and will pass on the other limb at 4.27 pm at position angle of 216.3 degrees, whereas Maximum Eclipse will be observed at 1.20 pm (in the afternoon).