Science (086) — AI-generated practice question

Similarity in symptoms: Both presbyopia and hypermetropia cause difficulty in seeing nearby objects clearly. In both conditions, the near point recedes beyond 25 cm, and a convex (converging) lens is used for correction.

Difference in cause:

• Hypermetropia is caused by the focal length of the eye lens being too long, or the eyeball being too small, so light from nearby objects focuses behind the retina.
• Presbyopia is caused by the gradual weakening of the ciliary muscles and diminishing flexibility of the eye lens due to ageing, leading to loss of power of accommodation.

Source: Human Eye and Colourful World, Section 10.2

---

Examiners expect you to clearly separate the two parts — similarity (symptom: can't see nearby objects) and difference (cause). For full marks, name the specific causes of each defect. Don't just say "old age" for presbyopia — mention ciliary muscles and flexibility of the lens. The correction (convex lens) can be mentioned as part of the similarity to strengthen the answer.