The document discusses the structure and function of the human eye. It describes the main parts of the eye including the cornea, iris, pupil, lens, vitreous humour, retina, and optic nerve. It explains how light enters the eye and is focused onto the retina, where it is converted into electrical signals that are sent to the brain. The document also briefly mentions accommodation, common vision defects and their correction, dispersion of light, rainbow formation, atmospheric refraction, scattering of light, and why the sky appears blue.

1. Human Eye & the
Colourful World 🌎 ✨️
By Maithili Bhanushali, Grade10

2. Structure of Human Eye

3.  Cornea – Light enters the eye through a thin membrane. It forms a
transparent bulge on front surface of the eyeball. Most of the refraction
occurs here.
 Sclera – It is the outer covering, protective tough white layer.
 Eyeball – The eyeball is spherical in shape with a diameter of about 2.3cm
 Aqueous Humour – It is a fluid which fills the space between cornea & the
eye lens.
 Iris – It is a dark muscular diaphragm that controls the size of the pupil.

4.  Pupil – It is a small opening in the middle of the iris through which light enters
the eye.It regulates & controls the amount of light entering the eye.
 Lens – Behind the pupil, there is a transparent & flexible jelly-like structure
called lens.
 Ciliary muscles – They are capable of modifying the curvature of the lens &
affecting focal length of the lens.
 Vitreous Humour – This fluid helps the eye hold its shape, with light being
transmitted through it to the retina.
 Retina – It is a light sensitive screen on which the image is formed & converts
the image formed by the lens to electrical impulses.
 Optic Nerve – These are the nerves which take the image to the brain in the
form of electrical impulses.

6. Power Of Accommodation

7. Defects of Vision & their Correction
1) Myopia (near – sightedness)

8. 2)Hypermetropia(Far – sightedness)

9. 3)Presbyopia

10. Dispersion of white light by prism

11. Rainbow Formation 🌈

12. Atmospheric Refraction

14. Scattering Of Light

15. Why is the colour of the Sky Blue?