The correct option is 2 and 3 only
Explanation
The human eye functions as an optical instrument capable of adjusting its focal length to see objects at varying distances. This ability is known as accommodation. The range of vision is defined by the near point and the far point.
- Statement 1 is Incorrect: The near point, also known as the least distance of distinct vision, is the closest distance at which the eye can focus clearly without strain. For a young adult with normal vision, this distance is typically 25 cm. A near point of 50 cm or more usually indicates a defect such as hypermetropia or presbyopia (aging eye).
- Statement 2 is Correct: The far point is the maximum distance at which the eye can see objects clearly. For a normal human eye, the far point is at infinity. This allows the eye to focus on distant objects like stars.
- Statement 3 is Correct: The range of vision for a normal eye extends from the near point (25 cm) to the far point (infinity). The ciliary muscles modify the curvature of the eye lens to ensure that objects located anywhere within this interval are focused sharply on the retina.
Key Takeaway: A normal human eye has a range of vision from 25 cm (near point) to infinity (far point). The eye adjusts its focal length to see clearly within this range through the process of accommodation.