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Light beams
Unless it enters your
eyes, light is invisible.
The beam of light
from a lighthouse can
only be seen from the
side if it catches mist
or dust in the air,
causing some of the
light rays to bounce
off towards you.
Lighthouse beams
sweep round in circles
and can be seen from
far out at sea.
Light
Convex mirrors bulge
outwards. They make
things look smaller
but let you see a
wider area.
Concave mirrors
bulge inwards. They
make things look
bigger but show a
smaller area.
Light. It travels at a thousand millions kph (620,000,000 mph).
How your eye works
The human eye works like a camera. The front
parts of the eye focus light rays just as a camera
lens does. The focused rays form an upside-down
image in the back of your eyeball.
Tree
2. The cornea
(front of eye) and
lens focus the rays.
3. An image forms on
the back of the eye.
Light-sensing cells send
the image to the brain.
4. The brain turns
the image the right
way up.
1. Light rays
from the tree
enter your eye.
Reflecting light
When light hits a
mirror, it bounces
straight back off.
If you look into a
mirror, you see this
bounced light as
a reflection.
Light enters your eyes through your pupils (the black circles in the
middle). Pupils can change size. When it’s dark they get bigger to let
more light in, and when it’s bright they shrink so you don’t get dazzled.
Dark
Bright
Lens
Cornea
