The Human Eye and the Colourful World Important Questions

The Human Eye and the Colourful World Important Questions

2013

Questions appearing in the 2013 Secondary Examination or the 2013 Secondary Supplementary Examination covered:

Defects of Vision and Correction: The cause and correction of hypermetropia (long sightedness).
Refraction and Dispersion: Defining prism angle and angle of deviation, and mentioning the sequence of colours in the spectrum.
Laws of Refraction: Question regarding the formula for refractive index (Snell’s Law application).
Atmospheric Phenomena: Defining the scattering of light, and explaining why the sun appears red at sunrise and sunset.

2014

Questions appearing in the 2014 Secondary Examination covered:

Eye Function: Which part of the eye adjusts the size of the pupil.
Defects of Vision: General questions asking for the two major defects of the eye, their causes, and correction methods.
Atmospheric Phenomena: Why the sky appears dark to an astronaut.

2015

Questions appearing in the 2015 Secondary Examination covered:

Eye Function: Defining the ability of the eye lens to adjust its focal length (power of accommodation).
Dispersion and Refraction: Defining the dispersion of white light, its cause, and demanding a diagram showing dispersion through a prism. It also included drawing a labelled diagram to show the refraction of light when traveling from air into glass and back into air.

2016

Questions appearing in the 2016 Secondary Examination covered:

Vision Defects: Drawing the ray diagram of an eye suffering from short sightedness (myopia).
Dispersion and Phenomena: Drawing the ray diagram for refraction of light through a prism and explaining the phenomenon of dispersion of light.
Atmospheric Phenomena: Explaining atmospheric refraction and advance sunrise, why stars twinkle, and why danger signals are red. It also included a brief definition of the Tyndall effect.

2017

Questions appearing in the 2017 Secondary Examination or the 2017 Secondary Special Supplementary Examination covered:

Eye Function: The value of the ‘least distance of distinct vision’ for a young adult with normal vision.
Defects and Correction: Identifying the defect and corrective lens when a person cannot see nearby objects. Naming two common defects of vision and the type of lenses used to correct them.
General Vision: Explaining the importance of good vision for safe driving, and defining dispersion of white light.

2018

Questions appearing in the 2018 Secondary Examination or the 2018 Secondary Supplementary Examination covered:

Eye Structure and Function: Drawing a labelled diagram of the human eye structure. Defining power of accommodation and visibility range of eye.
Defects and Correction: Defining astigmatism and explaining its correction. Asking which lens is used in remedies of astigmatism.
Atmospheric Phenomena: Explaining stars twinkle, advance sunrise and delayed sunset due to atmospheric refraction, and demanding a definition for the total internal reflection of light.

2019

Questions appearing in the 2019 Secondary Examination included questions requiring the definition of “Least distance of distinct vision” and listing the far point and near point of the human eye.

2020

Questions appearing in the 2020 Secondary Examination or the 2020 Secondary Supplementary Examination covered:

Driving Safety: Explaining the importance of good vision for safe driving.
Defects and Correction: Defining hypermetropia or long sightedness and how it is corrected, including drawing the ray diagram. Asking what is the far point and near point of the human eye.

2024

Questions appearing in the 2024 Secondary Examination or the 2024 Secondary Supplementary Examination covered:

Eye Function: Asking which part of the eye controls the size of the pupil (via muscles of the iris), and which lens is useful in correcting far-sightedness and nearsightedness.
Refraction and Wavelength: In the phenomenon of refraction of light, which colour has the maximum wavelength.
Dispersion: Defining dispersion of light.

HOME

I. The Human Eye: Structure and Function

Question	Answer (Source Text)
What is the ability of the eye lens to adjust its focal length called?	It is called the power of accommodation of the eye.
What is meant by power of accommodation of the eye?	The ability of the eye lens to adjust its focal length. (This definition is implied by the related question, though a formal definition is requested alongside the “visibility range of eye”).
Which part of an eye adjusts the size of its pupil?	This is adjusted by the iris.
The muscles of the iris controls… (C) Size of pupil (D) Shape of crystalline lens.	The muscles of the iris control the Size of pupil (C).
Write value of the ‘least distance of distinct vision’ for a young adult with normal vision.	The value is 25 cm.
What is the far point and near point of the human eye with normal vision?	The concepts of far point and near point of the eye are defined as important parts of vision (Near point is 25 cm, but the far point value is implied to be infinity, though not explicitly stated in the sources).
Explain the importance of good vision for safe driving.	The importance of good vision for safe driving must be explained. Related safety precautions like wearing a helmet are also addressed.

II. Defects of Vision and Correction

Question	Answer (Source Text)
Why is hypermetropia caused? How can it be corrected?	The source asks why hypermetropia (long sightedness) is caused and states that it can be corrected. The defect is corrected using a convex lens.
A person cannot see nearby objects, then write name of eye defect. Write name of lens used to correct this eye defect.	The defect is long sightedness (hypermetropia), and the correcting lens used is a convex lens.
What is astigmatism? How is this defect corrected?	Astigmatism is a defect of the human eye. The source questions how this defect is corrected.
Which lens is used in remedies of astigmatism?	The specific lens type used to correct astigmatism is requested.
$\text{……….. lens is useful in correcting far-sightedness.}$	The lens useful in correcting far-sightedness (hypermetropia) is the convex lens.
$\text{……….. lens is useful in correcting nearsightedness.}$	The lens useful in correcting nearsightedness (myopia) is the concave lens.
The ratio of image-distance (v) and object-distance (u) represent the _____ by a lens.	The ratio represents the magnification by a lens.

III. Refraction, Dispersion, and Scattering Phenomena

Question	Answer (Source Text)
Define dispersion of white light.	Dispersion of white light is requested to be defined. (It refers to the splitting of white light into its constituent colors, as suggested by the associated diagrams and questions).
Define prism angle and angle of deviation for a prism. Write the sequence of colours in the spectrum formed by the passage of white light through a prism.	The definition of prism angle and angle of deviation are requested. The sequence of colours in the spectrum must also be written.
In the phenomenon of refraction of light, if $\sin i = a$ and $\sin r = b$, then refractive index $(\mu)$ will be…	Based on Snell’s Law, the refractive index $(\mu)$ will be $\frac{a}{b}$.
What does mean by the total internal reflection of light?	Total internal reflection of light must be defined.
What is scattering of light?	Scattering of light must be defined.
In brief define ‘Tyndall effect’.	The Tyndall effect must be defined briefly.
Why does the sun appear red at sunrise and sunset?	The source asks for the reason why the sun appears red at sunrise and sunset.
Advance sunrise and delayed sunset are due to…	They are due to atmospheric refraction.
Why do stars twinkle?	The source asks why stars twinkle.
Why are the danger signals red in colour?	The source asks why danger signals are red in colour.
Which of the following colour has the maximum wavelength…? (A) yellow (B) red (C) violet (D) green	The color having the maximum wavelength is red (B).
Why does the sky appear dark to an astronaut?	The source asks why the sky appears dark to an astronaut.