Hint: A lens is an optical device that disperses a light beam using refraction. There are two types of lenses namely concave lens and convex lens. A simple lens consists of a single piece while a compound lens consists of several lenses.
Complete answer:
Myopia is also called nearsightedness. It indicates the inability to see the distant objects clearly and the close objects are visible clearly. It produces a blurry image as the eye converges the rays from a distant object in front of the retina and when they strike the retina they become divergent. Headache and eye strain are common symptoms. This can be corrected by using a concave lens and it is placed in front of the myopic eye.
Hypermetropia is also called longsightedness. It indicates the inability to see the nearby objects clearly and the distant objects are visible clearly. In this, the nearby objects are focused at a location behind the retina. This can be corrected by using a convex lens. If the power to focus is too weak and if the eye is too short, the image will go to the wrong place.
If farsighted, then wearing the glasses at the time of reading or while working on the computer is sufficient.
Thus the concave lens is used to correct myopia and the convex lens is used to correct hypermetropia.
Hence the correct option is D.
Note: 1. Hypermetropia is a hereditary condition. The symptoms of hypermetropia are blurry vision at night, eyestrain, headaches, and mostly trouble with reading.
2. After the age of 40 years, almost everyone experiences some degree of presbyopia.
I'm a vision science enthusiast with a deep understanding of optics and eye conditions. My knowledge is rooted in the principles of refraction and the functioning of lenses in correcting visual impairments. Now, let's delve into the concepts discussed in the article about myopia, hypermetropia, concave lenses, and convex lenses.
Myopia, also known as nearsightedness, is a condition where distant objects appear blurry, while close objects are clear. This occurs because the eye converges the rays from distant objects in front of the retina, leading to a divergent image on the retina. Common symptoms include headaches and eye strain. To correct myopia, a concave lens is used, which helps focus the image directly on the retina, allowing clear vision of distant objects.
On the other hand, hypermetropia, or farsightedness, is characterized by the inability to see nearby objects clearly, with distant objects being more visible. In hypermetropia, nearby objects are focused behind the retina. This condition can be corrected by using a convex lens, which adjusts the focal point and allows clear vision of nearby objects. In cases where the eye's power to focus is weak, especially during activities like reading or computer work, wearing glasses with convex lenses is recommended.
So, in summary, a concave lens is used to correct myopia by bringing the focus directly onto the retina, while a convex lens corrects hypermetropia by adjusting the focal point for clear vision of nearby objects.
Additionally, it's worth noting that hypermetropia is often hereditary, and its symptoms include blurry vision at night, eyestrain, headaches, and difficulties with reading. Another important point is that after the age of 40, many individuals experience presbyopia to some degree, a condition that affects near vision.
