Question

Eye lens is a

• A. Transparent Plano Concave Lens.
• B. Transparent Double-Convex Lens.
• C. Transparent Double-Concave Lens.
• D. Transparent Concavo - Convex Lens.

Answer 1

The correct option is B

Transparent Double-Convex Lens.

Explanation in case of correct option:

In case of correct option B.

1. The lens present in the eye refracts the light and focuses this light on the retina.
2. Unlike the normal lens, the biconvex lens in the eye can change its shape.
3. The shape of the lens automatically changes to adjust the focal length of the eye, So allowing the eye to focus clearly on the objects at different distances.
4. Thus biconvex or transparent double convex lens suits the eye most.

Explanation in case of incorrect options:

In case of option A.

1. They have a negative focal length and are used to diverge incoming light or to increase focal length in an existing optical system.
2. Our eyes don't need any diverging effect as it gives us the exact image of a thing near or far.
3. So this option is incorrect.

In case of option C.

1. This type of lens forms a virtual image on the same side of the lens as the object being viewed.
2. Therefore, a concave lens would focus the image in front of the eye, not on the retina inside the eye.
3. No signals would be sent to the brain so vision would not be possible.
4. So this option is incorrect.

In case of option D.

1. A Concavo-convex lens is a type of convex lens in which one side is convex (bulged out).
2. And another side is concave such that it is thick in the middle and thin at its edges (which is as like as the shape of a crescent moon).
3. Concave lenses are for the nearsighted, Convex for the farsighted. Concave lenses are used in eyeglasses that correct nearsightedness.
4. They are only used when there is a defect in the eye. Using them both as an eye lens will disrupt eyesight.
5. So this option is also incorrect.

Hence, option B is correct.