2.6.03 - see photographs of this year's eclipse on www.caithness.org
SAFE SUN - VIEWING THE SOLAR
For information about this year's Far North
eclipse and good locations to view, try this link,
but please read this first!
What is an Eclipse?
An eclipse occurs when the sun, earth and
moon are in alignment, with the moon situated between the earth and the
sun. When this happens the moon casts a shadow on the earth causing an
The sun is 400 times the diameter of the moon
but it is also 400 times further away from the earth. This causes the two
objects to look as though they are the same size when seen from the earth.
In a solar eclipse, the moon moves between
the earth and the sun. When this happens, part of the sun's light is
blocked. The sky slowly gets dark as the moon moves in front of the sun.
When the moon and the sun are in a perfect line, it is called a total
Looking at the Sun
The sun is the brightest object in the sky.
Looking directly at the sun or even near to the sun can cause damage to
the part of your eye called the retina, which can lead to blindness.
Viewing an Eclipse
It is never safe to look at the sun
directly. People have suffered eye damage after gazing at eclipses for as
little as 5 seconds.
There is a strong temptation during a solar
eclipse to stare at it. Many people who damage their eyes by looking
directly at the sun do so during an eclipse. RNIB is particularly
concerned about the safety of children's eyes during the eclipse as many
children have damaged their sight because they accidentally looked
directly at the sun during an eclipse.
The total eclipse, when the moon totally
covers the sun, lasts a very short time. Anyone who looks at the total
eclipse risks lasting eye damage because the sun emerges again without
How can I view the eclipse safely?
What the experts say:
The RNIB, the Royal College of
Ophthalmologists, the College of Optometrists and the Association of
Optometrists and all are agreed that direct viewing of the sun during an
eclipse is hazardous. The safest way of viewing the eclipse is by indirect
viewing (e.g. by using a pinhole viewer).
A Ďpinhole viewerí is an indirect way of
viewing an eclipse. A pinhole viewer is made from two pieces of cardboard,
one of which has a pin sized hole in it. The card with the pinhole in is
used to cast the image of the sun on onto the second card which should be
placed a half-metre or more from the first. Do not look directly at the
sun through the hole.
It is important to keep an eye on children
while using pinhole viewers in case they forget and look directly at the
See the 'How to make a pinhole viewer' section at
the end of this factsheet.
You may have seen, or been offered, a pair of
cardboard spectacles to view the eclipse.
These viewers are often called "mylar specs"
after the material used by scientists. Scientists and astronomers observe
eclipses for scientific reasons and they use specially constructed
equipment including aluminised mylar manufactured specifically for solar
observation. This material lets less than 0.003% of the sun's light
through, and no more than 0.5% of near-infrared radiation.
There are concerns about amount of protection
offered by some of these publicly available "viewing specs" because:
If you do decide to use a
solar filter or a pair of eclipse viewers you do so at your own risk. If
you do choose this method, the Department of Trade and Industry advises
that the viewer should bear a CE mark and should come with full instructions for
use. The CE mark means that the viewer has been approved under the personal
Protective Equipment Directive, and conforms to the Standard EN 169:1992
Ensure that the viewer fits closely to your
face and does not allow the sunís harmful rays to reach your eyes.
Remember - looking at the sun directly can cause serious eye damage or
blindness and the safest way of viewing the eclipse is indirectly using a
Other spectacles and filters:
It is not safe to look directly at the sun
through exposed film, or smoked glass.
It is not safe to look directly at the sun
through sunglasses, even good quality sunglasses (those that are UV400 or
UV 540 and conform to British or European safety standards).
Looking at the sun through a telescope or
binoculars will increase the power of the sun's harmful rays and would
almost certainly lead to serious eye damage or blindness.
For further Information:
If you or anyone you know has a serious sight
problem RNIB can help.
Call the RNIB Helpline for advice and
information: 0345-66 99 99
(Monday to Friday 9.00am - 5.00pm for the
cost of a local call)
How to Make A Pinhole Viewer