Question

A person uses lenses of power -0.5 D in his spectacles for the correction of his vision. (a) Name the defect of vision the person is suffering from.

Hint:

Myopia (nearsightedness) is corrected using concave lenses, which diverge light rays to focus images on the retina.

Answer 1

Step 1: Lens Power Explained

• The lens has a power of -0.5 D (diopters).
• The negative sign signifies a concave (diverging) lens.

Step 2: What Does a Concave Lens Fix?

• Concave lenses correct myopia (also known as short-sightedness).
• In myopia, close objects are clear, while distant objects appear blurry.

Step 3: Conclusion

The individual has myopia (short-sightedness). Therefore, they use a concave lens with negative power to improve vision.