Looking at the sun is always dangerous, but a partial solar eclipse may prompt people to look directly at the sun, which can result in permanent damage to the retina -- known as retinopathy. Exposure is not painful and damage may take several days to develop.
It can result in permanent visual loss and there is no treatment, according to the Australian Society of Ophthalmologists (ASO).
Even when 99 percent of the sun's surface is blocked out, the remaining one percent -- the photospheric crescent -- can be harmful to the eye.
So, experts warn to never look directly at the Sun, not even through a hole, or even worse through any optical device such as binoculars or a telescope.
Tourism Tropical North Queensland and NASA are providing a live stream of the full eclipse.
UNSW School of Physics' Dr Michael Ashley says the best way to watch the show safely is to buy proper eclipse-watching glasses.
“The safest way is to wear eclipse goggles or deep-welding goggles, but they must have the right grade filter, or you can damage your eyes,” he says. But he warns, even when wearing glasses, not to look at the sun for too long in case the lens is not working properly.
If you don't have any eclipse glasses, number 14 welder's glasses are a safe option.
Alternatively, another safe method is by PROJECTION.
(Image by ASO)
Stand with your back facing the sun and hold out a large piece of card with a small hole (2mm), so the sunlight can pass through the hole and project on to another piece of paper. The sunlight will pass through the pinhole and form an image on the screen.
Binoculars can be used to magnify an image of the Sun onto a white card. However, never look at the Sun directly.
CREATE A PIN-HOLE PROJECTOR
You can also create a pin-hole projector using a long box, at least six feet long, a piece of aluminium foil, a pin and a sheet of white paper.
Cut a hole in the centre of one end of the box. Tape a piece of foil over the hole. Poke a small hole in the foil with a pin and then cut a viewing hole on the side of the box. Put a piece of paper on the other side of the box. Point the side of the box with the pinhole at the sun. The round spot of light you will see projected on the white paper is an image of the Sun. Never look at the Sun directly through the pin-hole.
The length of the box is important. The longer the box, the bigger the pin-hole image.
More simply, you can create a basic projection by interlacing your fingers and letting the light filter through them onto a surface on the ground. Just hold up your hands with your fingers at right angles - the holes between your hands make pin-holes. You can then watch the projection on a white piece of paper on the ground.
SPECIALISED CAMERA FILTERS
Specialised camera filters can be used to take photos of the eclipse, but they must be especially made for this purpose. Do not use regular polarisers and filters as they won't protect your eyes.
Although solar eclipses occur fairly frequently, Dr Ashley says they are rarer than lunar eclipses, which can be seen from anywhere on earth.
The next solar eclipse to grace Australian skies will be on July 22, 2028, so he encourages people to take advantage of this eclipse.
"It's a once-in-a-lifetime experience,” Dr Ashley said.
To learn more about tomorrow's eclipse, see this factsheet by the Astronomical Society of Australia.
