Class 10 Science Chapter 10 (formerly Chapter 11), The Human Eye and the Colourful World, applies refraction of light to the structure and defects of the human eye, refraction through a triangular glass prism, dispersion of white light into a spectrum, rainbow formation, atmospheric refraction, and Tyndall scattering.
What Class 10 Science Chapter 10 Covers
10.1 & 10.2 The Human Eye, Power of Accommodation & Defects of Vision describes the cornea, iris, pupil, crystalline lens, ciliary muscles and retina, defines the power of accommodation, near point ($25\text{ cm}$ for a normal eye) and far point (infinity), and explains the causes and corrective lenses for myopia (near-sightedness, corrected with a concave lens), hypermetropia (far-sightedness, corrected with a convex lens) and presbyopia (bifocal lenses).
10.3, 10.4 & 10.5 Prism Refraction, Dispersion & Atmospheric Refraction traces the angle of deviation ($\angle D$) through a glass prism, Newton’s two-prism recombination of the white-light spectrum (VIBGYOR), rainbow formation by dispersion, internal reflection and refraction in raindrops, twinkling of stars vs non-twinkling planets, and advance sunrise / delayed sunset ($2\text{ minutes}$ each).
10.6 Scattering of Light explains the Tyndall effect in colloidal solutions and forest canopies, and why the clear sky appears blue to observers on Earth while appearing dark to astronauts in space.
Exercises in Chapter 10
- In-text Questions cover what is meant by the power of accommodation of the eye, the far point and near point of a normal human eye, and why a normal eye cannot clearly see objects placed closer than $25\text{ cm}$.
- Chapter Exercises (12 Questions) include numericals on corrective lens power for myopic and hypermetropic eyes, why stars twinkle while planets do not, and why the sky appears dark instead of blue to an astronaut.
Read Class 10 Science Chapter 10 Online
More Chapters
- Previous: Chapter 9: Light – Reflection and Refraction
- Next: Chapter 11: Electricity
- Hindi medium: Class 10 Science Chapter 10 PDF in Hindi (Vigyan)
- All Science chapters and the other Class 10 books: Class 10 NCERT books 2026-27
- All Class 1 to 12 NCERT Textbooks: NCERT Books PDF (Class 1–12)
FAQ
Why do stars twinkle while planets do not?
Stars are point-sized sources of light very far away; as starlight enters Earth’s atmosphere of continually changing refractive index, its apparent position and brightness fluctuate, causing twinkling. Planets are much closer and act as extended collections of many point sources whose fluctuations average out to zero.
What is myopia and how is it corrected?
Myopia (near-sightedness) is a defect in which a person can see nearby objects clearly but cannot see distant objects distinctly because the image forms in front of the retina (due to excessive curvature of the eye lens or elongation of the eyeball). It is corrected using a concave (diverging) lens of suitable power.