Which vision defect is characterized by a near point that has receded beyond the normal distance of 25 cm, while the far point remains at infinity?

The correct option is Hypermetropia

Explanation

Vision defects, also known as refractive errors, occur when the eye cannot properly focus images on the retina. These defects are primarily categorized by how they affect the near point and far point of vision.

Statement-wise Analysis

The question describes a vision defect where the near point has receded beyond the normal distance of 25 cm, while the far point remains at infinity. 1. Myopia (I Myopia, or nearsightedness, is characterized by the far point being at a finite distance rather than infinity. The near point in myopic individuals is typically closer than 25 cm. Therefore, this option is incorrect. 2. Hypermetropia (Correct): Hypermetropia, or farsightedness, is a condition where the eye can see distant objects clearly but has difficulty focusing on near objects. This occurs because the light rays from a near object converge behind the retina. Consequently, the near point of the eye recedes, meaning the person must hold objects further away than 25 cm to see them clearly. The far point, however, remains at infinity, allowing clear distant vision. 3. Presbyopia (Incorrect): Presbyopia is an age-related vision defect where the eye's lens loses its flexibility, making it difficult to focus on near objects. Similar to hypermetropia, the near point recedes. However, presbyopia is specifically due to the hardening of the lens and weakening of ciliary muscles, and it is distinct from hypermetropia which can occur at any age due to a shorter eyeball or less converging power of the lens. The question describes a general condition of near point recession with a normal far point, which aligns with the definition of hypermetropia. 4. Cataract (Incorrect): Cataract is a condition where the eye's natural lens becomes cloudy, leading to blurred vision. It is not primarily characterized by a change in the near or far point in the manner described but rather by a general clouding of vision. Therefore, this option is incorrect. Key Takeaway: Hypermetropia is the vision defect where the near point recedes beyond 25 cm, while the far point remains at infinity, indicating clear distant vision but difficulty with near vision.