Science · Class 10
Human Eye and Colourful World
Eye structure, defects of vision, and dispersion of light.
3 sections15–25 min read6 MCQs · 2 examples
Chapter Overview
The human eye forms images on the retina; defects are corrected with lenses. Atmospheric refraction, scattering of light, dispersion through prism, and rainbow formation explain the colourful world.
Human Eye
- Cornea, iris, pupil, lens, retina, optic nerve
- Accommodation: ciliary muscles change lens curvature
- Myopia: distant blur — concave lens; Hypermetropia: near blur — convex lens
- Presbyopia: aged-related loss of accommodation
Dispersion & Scattering
- White light splits into VIBGYOR in prism
- Blue sky: Rayleigh scattering — shorter λ scattered more
- Red sunset: longer path, blue scattered away
- Rainbow: dispersion + internal reflection in droplets
Solved Examples
Step-by-step solutions — read each step before checking the final answer.
Myopia correction
A myopic person cannot see distant objects. Lens?
- 1Image forms before retina
- 2Need diverging lens
- 3Concave lens spreads rays
Answer
Concave (diverging) lens
Why sky is blue
Explain blue colour of sky.
- 1Sunlight has all colours
- 2Air molecules scatter shorter wavelengths more
- 3Blue scattered across sky
Answer
Scattering of blue light by atmosphere
Key Points to Remember
- ✓ Persistence of vision ~1/16 s
- ✓ Twinkling of stars: atmospheric refraction
- ✓ Danger signals red: least scattered
Exam Tips
- • Draw ray diagrams for eye defects
- • Know lens used for each defect
- • Explain dispersion with prism diagram
Practice MCQs — Human Eye and Colourful World
Test your understanding with topic-wise multiple choice questions. Explanations appear after each answer.
Question 1 of 6Score: 0/0
Myopia is corrected by: