Question

What is Myopia? Give its reasons. Explain with the help of the labelled ray diagram, how it is corrected.

Answer 1

Hint: Myopia is the eye defect in which humans can’t see objects at a distance from the eye clearly. The object appears blurry to them and this is the common problem of sight that is faced by small children.

Complete step by step solution:
The two eye-sight defects of the human eye are the myopia and hypermetropia. The name myopia is the defect in which the object far from the eyes is not clear and it is also called short sightedness. The defect hypermetropia is one in which the object near the eye does not appear clear to the human eye and is called the long sightedness.

Myopia is the most common sight problem faced by the young people. This defect arises when the eye grows long from the front part of the eye to its back part such that the light that comes from the distance to the focus is not inside the eye but in front of the eye retina. In myopia the other factor that causes it is the cornea of the eye that gets curved to the eyeball length, that is it gets too thick.

The labelled ray diagram is shown in the below figure.

                                                                                    Figure 1

The above diagram shows that when the light comes from the object at a distance and passes through the eye lens the focus of the image is in front of the retina in case of myopic eye but for a healthy and correct eye it should be on the retina.

Note: Regular complaining of headaches or tired eyes or water coming from the eyes and regularly rubbing their eyes are the signs of myopia and it is also known as the short-sightedness. For the children to avoid this problem make a habit of sitting not close to television sets.