A person has concave lenses in his spectacles. which defect of vision is he suffering from?
Answers
Myopia / Nearsightedness
The person who is advised to wear spectacles of concave lenses is suffering from eye defect of
myopia (nearsightedness).
1. A person suffering from myopia can say e nearby objects clearly as the image of a nearby object is formed on the retina, but cannot see distant objects clearly as the image of a distant object is formed in front of the retina instead of on the retina.
2. A concave lens diverges the rays of light passing through it.
3. When spectacles of concave lens of appropriate power are used, the parallel rays coming from a distant object are diverged to proper extent before they are incident on the eye lens.
Therefore, after the converging action of the eye lens, the image of a distant object is formed on the retina of the eye and hence the distant object can be seen clearly.