Question 1

What is the function of the cornea in the human eye?

Accepted Answer

The cornea is the outermost, transparent, and bulging part of the human eye that covers the front portion. Its primary function is to act as the primary window of the eye and refract or bend most of the incoming light rays so that they can pass through the pupil and lens to focus properly on the ret

Question 2

Define the term 'power of accommodation' of the human eye.

Accepted Answer

The power of accommodation refers to the remarkable ability of the human eye's crystalline lens to adjust its focal length by changing its curvature with the help of the ciliary muscles. This automatic adjustment enables the eye to clearly and distinctly focus on objects situated at varying distance

Question 3

What is myopia and how is it corrected?

Accepted Answer

Myopia, also commonly known as near-sightedness, is a common vision defect in which a human eye can see nearby objects clearly, but distant objects appear blurred because the image is formed in front of the retina rather than directly on it. This defect is corrected by using a concave lens of approp

Question 4

Why do stars twinkle at night? Explain briefly.

Accepted Answer

Stars twinkle at night primarily due to the atmospheric refraction of starlight. As the light rays coming from distant stars enter the Earth's atmosphere, they pass through varying layers of air that have different temperatures, densities, and refractive indices. These layers constantly shift and ca

Question 5

Why does the clear sky appear blue during a sunny day?

Accepted Answer

The clear sky appears blue during the day because of the phenomenon of Rayleigh scattering of sunlight by the molecules of air and fine particles in the Earth's atmosphere. Molecules scatter shorter wavelengths of light, such as blue and violet, much more effectively than longer wavelengths like red

The Human Eye and Colourful World