Q. Which of the following is/are correctly matched?
Vision Defect —–Correction Lens
1. Myopia —– Bifocal lens
2. Hypermetropia—–Convex lens
3. Presbyopia—–Concave lens
Select the correct answer using the codes given below:
Myopia: A person with Myopia can see nearby objects clearly. A person with myopia cannot see faraway objects clearly. The far point for the myopic eye is nearer than infinity occurs due to excessive curvature of the eye lens and elongation of the eyeball. The image of a distant object is formed in front of the retina and not on the retina
Defected is corrected by using Concave lenses such that the lens will bring the image back on to the retina.
Hypermetropia: A person with Hypermetropia can see far away objects clearly. A person with Hypermetropia cannot see nearby objects clearly. The near point of the eye is more than 25cm. This arises mostly during latter stages in life, as a result of the weakening of the ciliary muscles and/or the decreased flexibility of the lens. The image of a distant object is formed behind the retina and not on the retina.
Defected is corrected by using Convex lenses such that the lens will bring the image back on to the retina.
Presbyopia: The power of accommodation of the eye usually decreases with aging. The ciliary muscles weaken and thereby the flexibility of the eye lens reduces. The near point moves away. Spectacles with bifocal lenses are recommended.
Source: NCERT
