What you need to know when watching the eclipse

While we celebrate Uganda having the best view of the November 3 eclipse, there are some dos and don’ts to note so that we view it without getting hurt.

We all can’t wait, can we? To see that breathtaking moment when the moon blocks out the sun’s rays in what is known as the eclipse, which will take place on November 3, about three weeks from now.

As this day draws closer, there are certain dos and don’ts that everyone who is intending to watch the eclipse must put into consideration for their own safety.

Ben Enjiku, a senior lecturer of physics at Kyambogo University says during this time when the moon is obstructing the sun, the eye’s pupil will be dilated in order for it to absorb as much light as possible.

There will be no danger of course in looking at this spectacular sight. However, the issue only comes in as the moon is leaving the sun, thereafter casting its rays back onto the earth.

“The sun is the main source of ultraviolet light. In case you were staring at the eclipse with naked eyes and some of the rays penetrate into them, you will definitely get a problem,” Enjiku explains.

“This is because the widened pupil will be absorbing so much of the rays into the eye,” he adds.

Ultraviolet (UV) light is an invisible form of electromagnetic radiation that has a shorter wavelength which cannot be seen easily by humans. It carries more energy than the visible light and can occasionally break bonds between atoms and molecules, therefore altering the chemistry of materials exposed to it.

Danger to the eyes
The effects, according to Enjiku, include the UV light causing partial blindness to the eye, where by one fails to see the difference between certain things for instance colour.

Even worse, one can become completely blind as a result of the UV light damaging the retina.

Adults tend to notice the effects more quickly than children. It is therefore important that all children are monitored closely by the adults on that day.

BBC news on November 29, 2002 in a story titled “How to watch the eclipse safely” reported that there is no pain when the retina is being burned, and the resulting visual symptoms do not occur until at least several hours after the injury has occurred, by which time it is far too late.

The news agency also added that depending on how long the retina is exposed to the sun, this injury may cause permanent damage to vision.

What you can use
On how these dangers can be avoided, Enjiku advises people to use devices that will enable them see the eclipse clearly but block the UV light at the same time.

“You can use film negatives that were commonly used in cameras back in the day. The other option can be to get a transparent glass and smoke it until it becomes black in colour. The dark coating helps in cutting off the ultra violet light,” he adds. Some of the sources of smoke can be wood, dry grass or a candle.

The other safe method that Enjiku suggests for viewing the eclipse is putting water in a basin that is coated with black paint at the bottom, so that you see the eclipse on the water surface.

By Bruce Amp