External parts of Eye
Internal parts of Eye
Eye Working
Eye Blind Spot
When light lands on your retina, it sends electrical bursts through your optic nerve to your brain.
Your brain turns the signals into a picture. The spot where your optic nerve connects to your retina
has no light-sensitive cells, so you can't see anything there. That's your blind spot.
Focusing objects at different positions
Cameras and lenses
Cameras and lenses
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Optical instruments
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Why we see colour
DISPERSION OF LIGHT
Recombination of white light
When an inverted prism is kept a little distance away from the prism causing
dispersion or basically in the path of splitted beam, the spectrum recombines to
form white light.
Why we see a rainbow
A rainbow is a natural spectrum appearing in the sky after rain shower. It is caused by
dispersion of sunlight by tiny water droplets, present in the atmosphere. The water droplet act
like small prism. They refract and disperse the incident sunlight, then reflect it internally and
finally refract it again.
Due to dispersion of light and internal reflection different colours appears.
Why we see a double rainbow
Why we see a double rainbow
Atmospheric refraction :-
Twinkling of stars :-
The twinkling of stars is due to the atmospheric refraction of star light and
due to the changing in the position of the stars and the movement of the
layers of the atmosphere. So the light from the stars is sometimes brighter
and sometimes fainter and it appears to twinkle.
Planets are closer to the earth than stars. The light from stars are
considered as point source of light and the light from planets are considered
as extended source of light. So the light from the planets nullify the twinkling
effect.