Question

For an object distance of infinity, the focal length of the eye (the distance between the lens and the retina) is about

• A. 1 cm
• B. 1 mm
• C. 2.5 cm
• D. 2.5 mm

Answer 1

The correct option is C

2.5 cm

Explanation for correct answer:

1. Our eye has a convex lens present in it to enable us to see the entities around us.
2. This lens has a special property of adjusting its focal length depending upon the position of the object
3. As we know for an infinity object, the image is formed at the focus by a convex lens
4. The focal length of the eye is $2.5cm$ while viewing an infinity object.

Therefore, the correct option is (C)