CBSE · Class 10 · Science · Chapter 10
The Human Eye and the Colourful World — Class 10 Science (CBSE) explained
- Board exam 2026-27
- 4 lessons
- 28 scenes
- About 21 min
- Updated
Quick answer
The Human Eye and the Colourful World is Chapter 10 of CBSE Class 10 Science. It covers normal limits of distinct vision, cataract and refractive-defect overview, myopia and image position, hypermetropia and the receding near point, correction of hypermetropia and rainbow formation. AI Lessons teaches it in 4 narrated lessons (about 21 minutes) with an AI tutor and board-pattern practice.
What you’ll learn
Lesson 1: The Human Eye, Accommodation and Myopia
5 min- Meet the Eye's Optical System
- From Incoming Light to Visual Information
- Accommodation Changes the Lens
- Near Point and Far Point
- Cloudy Lens or Refractive Defect?
- Myopia Focuses Distant Images Too Early
- A Concave Lens Corrects Myopia
Lesson 2: Vision Correction and Eye Donation
5 min- Hypermetropia Focuses Nearby Images Too Late
- A Convex Lens Corrects Hypermetropia
- Presbyopia Reduces Accommodation
- Bi-focal Lenses Serve Two Viewing Needs
- Eye Donation and Corneal BlindnessNot assessed
- Who Can Donate Eyes?Not assessed
- The Eye Bank Handles DonationNot assessed
Lesson 3: Prisms, Dispersion and Rainbows
5 min- What Makes a Prism Different?
- Trace a Ray Through the Prism
- Two Refractions Produce Deviation
- White Light Produces a Spectrum
- Different Colours Bend Differently
- Recombining the Spectrum
- A Raindrop Produces a Natural Spectrum
Lesson 4: Atmospheric Refraction, Scattering and Practice
6 min- Changing Air Can Shift an Apparent Position
- Why Stars Twinkle
- Why Planets Do Not Twinkle
- The Sun Appears Before It Crosses the Horizon
- Scattering Makes a Beam's Path Visible
- Why the Sky Is Blue and Danger Signals Are Red
- Recap: Explain the Eye and the Colourful World
Key concepts
- Normal limits of distinct vision
- The farthest point of clear vision is called the far point. For a normal eye, it is infinity.
- Cataract and refractive-defect overview
- The three common refractive defects are myopia, hypermetropia and presbyopia. Suitable spherical lenses can correct these defects.
- Myopia and image position
- The important visual clue is the position of the distant object's image.
- Hypermetropia and the receding near point
- The near point is farther away than the normal near point of twenty five centimetres. Reading material must therefore be held much beyond that normal distance for comfortable reading.
- Correction of hypermetropia
- Hypermetropia is corrected using a convex lens of appropriate power.
- Rainbow formation
- A rainbow is always formed in the direction opposite to the Sun.
- Advance sunrise and delayed sunset
- Actual sunrise means the actual crossing of the horizon by the Sun.
- Scattering and the Tyndall effect
- The path of a light beam is not visible through a true solution. Through a colloidal solution, its path becomes visible.
Exam focus
- Board exam
- CBSE assesses this chapter in the 2026-27 year-end board examination.
- Syllabus
- Functioning of a lens in human eye, defects of vision and their corrections, applications of spherical mirrors and lenses. Refraction of light through a prism, dispersion of light, scattering of light, applications in daily life (excluding colour of the sun at sunrise and sunset).
- Not assessed
- These parts go beyond the 2026-27 syllabus and are taught for understanding only: Eye Donation and Corneal Blindness, Who Can Donate Eyes? and The Eye Bank Handles Donation.
- Exam note
- Colour of the sun at sunrise and sunset is excluded.
- Paper pattern
- 80 marks, 3 hours, 39 questions in three sections (A Biology, B Chemistry, C Physics); internal assessment 20. Units: I Chemical Substances 25, II World of Living 25, III Natural Phenomena 12, IV Effects of Current 13, V Natural Resources 5.
- Question style
- About 50% of board questions are competency-focused: case-based, source-based, integrated, data interpretation, situational and application-oriented.
- Practice in the app
- 81 board-pattern questions with marking schemes: 25 multiple choice (1 mark), 14 assertion–reason (1 mark), 16 very short answer (2 marks), 14 short answer (3 marks), 4 long answer (5 marks) and 8 case-based (4 marks).
Sample questions with marking points
Board-pattern questions from the AI Lessons practice set for this chapter. The marking points show what an examiner looks for; full model answers are in the app.
Very short answer2 marks
After a prism-tracing demonstration, the prism outline and all four pin marks remain on the paper. Explain how the path of the ray inside the prism is constructed.
Marking points
- Extend the incident pin line to locate the entry point E.0.5
- Extend the emergent pin line to locate the exit point F.0.5
- Join E and F to construct the internal refracted ray.1
Short answer3 marks
An older person develops increasing difficulty in reading nearby print as the near point gradually moves farther away. Examination also shows myopia. (a) Identify the age-related defect and state its two causes. (b) Describe the two portions of a common bi-focal lens prescribed for distant and near vision.
Marking points
- (a) Identifies the age-related defect as presbyopia.1
- (a) States gradual weakening of the ciliary muscles.0.5
- (a) States diminishing flexibility of the eye lens.0.5
- (b) Upper portion: concave lens for distant vision.0.5
- (b) Lower portion: convex lens for near vision.0.5
Long answer5 marks
Describe a two-prism demonstration that separates sunlight into its component colours and then recombines them. Explain why the colours separate, identify the colours with the least and greatest deviation, describe the arrangement of the second prism, and state what the final observation establishes.
Marking points
- The first prism produces a spectrum because different colours bend through different angles and emerge along different paths.1
- Red deviates least.0.5
- Violet deviates most.0.5
- The second prism is identical and inverted relative to the first.0.5
- All seven colours from the first prism are allowed to pass through the second.0.5
- The colours recombine and white light emerges from the second prism.1
- The observation establishes that sunlight consists of seven component colours.1
Frequently asked questions
What does The Human Eye and the Colourful World cover in Class 10 Science?
It covers normal limits of distinct vision, cataract and refractive-defect overview, myopia and image position, hypermetropia and the receding near point, correction of hypermetropia and rainbow formation. AI Lessons teaches it in 4 lessons: The Human Eye, Accommodation and Myopia, Vision Correction and Eye Donation, Prisms, Dispersion and Rainbows and Atmospheric Refraction, Scattering and Practice.
Is The Human Eye and the Colourful World in the CBSE Class 10 board exam?
Yes. CBSE assesses The Human Eye and the Colourful World in the 2026-27 year-end board examination. 3 short parts go beyond the syllabus and are marked as not assessed.
What is the far point?
The farthest point of clear vision is called the far point. For a normal eye, it is infinity.
What does actual sunrise mean?
Actual sunrise means the actual crossing of the horizon by the Sun.
What kinds of questions come from The Human Eye and the Colourful World?
Board-pattern questions for this chapter include multiple choice (1 mark), assertion–reason (1 mark), very short answer (2 marks), short answer (3 marks), long answer (5 marks) and case-based (4 marks). AI Lessons has 81 of them for The Human Eye and the Colourful World, each with a marking scheme.
How does AI Lessons teach The Human Eye and the Colourful World?
As 4 narrated, animated lessons (28 scenes, about 21 minutes in all), with an AI tutor that knows the step you are on and board-pattern practice with marking schemes. The full lessons open after sign-in on an AI Lessons account.
Watch the full lesson
The Human Eye and the Colourful World, as a narrated, animated lesson
4 lessons · 28 animated scenes · about 21 minutes, with an AI tutor that knows the step you are on and 81 board-pattern questions with marking schemes.
Lessons open after sign-in. A parent or guardian holds the account and adds each child.