Question

If the power of an eye lens increases, then the defect in vision so produced is known as,
(A) Colour blindness
(B) Long sightedness
(C) Short sightedness
(D) None of the above

Answer 1

Hint
This is the condition of our eyes in which the image, after being focused by the lens in our eyes, is formed in front of the retina rather than on the retina. This causes us to be able to see the distant objects as blurry and is known as nearsightedness.


Complete step by step answer
When light enters our eye, the lens focuses the light entering and thus forms an image on our retina, which consists of nerves that transmits that signal to our brain. But if the eyeball gets too elongated or the power of the lens increases, then in that case, the light rays are focused in front of the retina and the image is not perceived by our brain clearly.
Because of these conditions, a person may not be able to see clearly the images which are far away or see them blurry.
This specific condition of the eye is known as myopia and is also called short sightedness.
Hence the option (C) is correct.

Additional Information
The condition of myopia could be corrected by using glasses or contact lenses. Though glasses are easier to manage by the contact lenses provide a wider range of vision but are associated with risks of infection. Some surgeries or laser procedures can also help to cure short sightedness.

Note
The underlying cause for short sightedness can be considered to be a combination of genetic as well as environmental factors. The risk of myopia may be inherited from one’s parents. Environmental factors such as insufficient exposure to light, low physical activity or increased years of education can cause myopia or short sightedness.