Human Eye And Colourful World (VSAQs)

Physical Science | 5. Human Eye And Colourful World – VSAQs:
Welcome to VSAQs in Chapter 5: Human Eye And Colourful World. This page contains the most important VSAQs in this chapter. Aim to secure top marks in your exams by understanding these clear and straightforward Very Short Answer Questions.


VSAQ-1 : What would happen if ciliary muscles do not function properly?

If Ciliary Muscles Do Not Function Properly:

  1. Inability to Change Lens Shape:
    The eye lens would not be able to change its shape or adjust its focal length. This condition, known as presbyopia, can lead to difficulty focusing on nearby objects.
  2. Limited Range of Clear Vision:
    The range of clear vision will be limited, and the eye will have difficulty seeing objects at varying distances. The individual may experience blurred vision for both near and far objects, affecting their overall visual acuity.
  3. Essential for Accommodation:
    Proper functioning of the ciliary muscles is essential for the eye’s ability to accommodate and focus on objects at different distances.

VSAQ-2 : Which molecules of atmosphere act as scattering centers are responsible for the blue sky ?

  1. Oxygen and Nitrogen Molecules:
    Oxygen and nitrogen molecules in the Earth’s atmosphere are responsible for the scattering of sunlight, which causes the blue color of the sky.
  2. Shorter Wavelengths Scattered More:
    The shorter wavelengths of sunlight, such as blue and violet, are scattered more than the longer wavelengths like red and orange.
  3. Perception of Blue Sky:
    As a result, when we look up at the sky, we see the scattered blue light, giving the sky its characteristic blue color.
  4. Rayleigh Scattering Phenomenon:
    This phenomenon is known as Rayleigh scattering and is responsible for the blue color of the daytime sky.

VSAQ-3 : What happens if the eye lens is not able to adjust its focal length ?

  1. Condition of Presbyopia:
    If the eye lens is not able to adjust its focal length properly, a condition known as presbyopia occurs.
  2. Age-Related Loss of Focus:
    Presbyopia is the age-related loss of the eye’s ability to focus on nearby objects.
  3. Difficulty in Seeing Objects Up Close:
    As a result, the person will have difficulty seeing objects up close and may need reading glasses or corrective lenses for near vision.
  4. Reduced Focus on Varying Distances:
    Objects at a specific distance may be clear, but the ability to focus on objects at varying distances will be reduced, affecting overall visual clarity and comfort.

VSAQ-4 : A person is unable to see distance objects. Show the defect of vision of the person with the help of diagram.

  1. Myopia Overview:
    Myopia, also known as nearsightedness, is an eye disorder where the eyeball is too elongated, causing light rays to focus in front of the retina instead of directly on it.
  2. Effect on Vision:
    This results in distant objects appearing blurry.
  3. Illustrating Myopia with a Diagram:
    To illustrate this defect, a diagram can be drawn showing the elongated eyeball and the focal point falling in front of the retina for distant objects.
  4. Purpose of the Diagram:
    The diagram would help visually explain the condition of myopia and how it affects a person’s ability to see distant objects clearly.

VSAQ-5 : Write the reason for sun appearing red during the Sun-rise and Sun-set.

  1. Scattering of Light:
    The phenomenon of the sun appearing red during sunrise and sunset is due to the scattering of light in the Earth’s atmosphere.
  2. Longer Path Through Atmosphere:
    During these times, the sunlight travels a longer path through the atmosphere to reach our eyes.
  3. Shorter Wavelengths Scattered:
    The shorter wavelengths of light, such as blue and violet, get scattered and dispersed by the molecules in the air.
  4. Longer Wavelengths Less Affected:
    The longer wavelengths, such as red, are less affected and remain visible.
  5. Predominance of Red Light:
    As a result, the sun appears red or orange during these times due to the predominance of red light reaching our eyes.