Question

A person is wearing spectacles with concave lenses for correcting vision. While not using the glasses, the image of a distant object in his case will be formed.
A. On the blind spot
B. Behind the retina
C. In front of the retina
D. On the yellow spot

Answer 1

Hint:A concave lens is a lens that possesses at least one surface which curves inwards. It is a diverging lens which spreads out the light rays that have been refracted. A concave lens is thinner at its centre, and it is used to correct short sightedness called myopia.

Complete answer:
A concave lens is also called a diverging or negative lens. It is a type of optical lens where the surface of the glass is curved in an inward direction. And its outer surface somewhat resembles the cave.When a light ray falls on the surface of the lens then it bends the light rays which pass parallel to its principal axis. And the curvature of the lens is responsible for the direction which the ray bends.

In a concave lens, the centre is quite thinner than the edges thus the curve present in inward direction. So, when the light rays pass through it then it bends towards the single point.Thus, the concave lens is diverging in nature.

A lens refracts light and forms an image and the concave lens is thicker at the edges in the middle. This causes rays of light to diverge and this light forms a virtual image which is right-side up smaller than the object. Then the person wearing spectacles with a concave lens for correcting vision suffers from myopia.

Thus, the option C is correct.

Note: A concave lens is thinner in the middle than the edges. This causes parallel rays to diverge, they can separate but appear to come from the principle focus on the other side of the lens. A convex lens which is also called a converging lens or positive lens is thicker in the middle. The light rays that pass through a convex lens converge or are brought closer together. There are various uses of a convex lens like in a microscope, magnifying glasses, camera, correction of hypermetropia, etc.