Question

1) A student is not able to read topics written on the board but is able to read his books topics which is kept in his

hand. His friend talked to him about sightedness.

a) What are you thinking about his sightedness by which he is suffering from? Write its name.

b) What are the causes of such sightedness?

c) Which type of lens will be prescribed for him.​

Answer 1

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A) Near-sightedness, also known as short-sightedness and myopia, is an eye disorder where light focuses in front of, instead of on, the retina. This causes distant objects to be blurry while close objects appear normal. Other symptoms may include headaches and eye strain. Severe near-sightedness is associated with an increased risk of retinal detachment, cataracts, and glaucoma.

B) Short-sightedness usually occurs when the eyes grow slightly too long. This means that light doesn't focus on the light-sensitive tissue (retina) at the back of the eye properly. Instead, the light rays focus just in front of the retina, resulting in distant objects appearing blurred.

C) Near sightedness, or myopia, is the most common refractive error of the eye. Myopia occurs when the eyeball is too long, relative to the focusing power of the cornea and lens of the eye. This causes light rays to focus at a point in front of the retina, rather than directly on its surface. So, to treat myopia the glasses will be preceded by a minus sign ().

Hence, to treat myopia concave lens should be used.