The Human Eye and the Colourful World in Science

The human eyeis an organ that detects light and allows us to see. It works like a camera by focusing light onto the retina, which sends signals to the brain to form an image.

Parts of the Human Eye:

1. Cornea – Transparent outer layer that refracts light.
2. Pupil – The dark circular opening that controls the amount of light entering the eye.
3. Iris – The colored part of the eye that controls the size of the pupil.
4. Lens – Focuses light onto the retina.
5. Retina – The light-sensitive layer at the back of the eye where images are formed.
6. Optic Nerve – Transmits the visual information from the retina to the brain.

Working of the Eye:

• Light enters through the cornea and pupil.
• It is focused by the lens onto the retina.
• The retina converts the light into nerve signals, which are sent to the brain through the optic nerve.

The Colourful World:

The world appears colourful because light from the sun is made of different colours (the spectrum of light).

1. Dispersion of Light:When white light passes through a prism, it splits into its seven colours (violet, indigo, blue, green, yellow, orange, and red) — this is called dispersion.
2. The Formation of Rainbow: A rainbow is formed when sunlight is refracted and dispersed by water droplets in the sky, creating a spectrum of colours.
3. Why the Sky Appears Blue: The blue light from the sun is scattered more than other colours due to its shorter wavelength, making the sky look blue.