The ability of the eyes to focus on both near and distance objects is termed

Step 1: Analyze the question The question asks for the term describing the eye's ability to focus on both near and distant objects.

Step 2: Explain the concept The eye focuses by changing the shape (curvature) of the lens, mainly using the ciliary muscles and suspensory ligaments:

• Viewing a near object: The ciliary muscles contract, the suspensory ligaments slacken, and the lens becomes thicker (more convex). This increases its refractive power so that light from close objects is focused on the retina.
• Viewing a distant object: The ciliary muscles relax, the suspensory ligaments tighten, and the lens becomes thinner (flatter). This reduces its refractive power so that light from far objects is focused on the retina.

This adjustment of the lens is called accommodation.

Step 3: Check each option

• A. Image formation: This is the general process of forming an image on the retina. It does not describe adjusting focus between near and far.
• B. Refraction: This is the bending of light as it passes through the cornea, aqueous humour, lens, and so on. It is part of how the eye works, but it is not the ability to adjust focus.
• C. Hypermetropia: This is long-sightedness, a defect in which near objects appear blurred. It is not a normal ability.
• D. Accommodation: This is the ability of the eye to adjust the lens to focus on near and distant objects. ✔

Step 4: Answer The correct option is **D.

Exam tip: Think of "accommodation" as the eye accommodating (adjusting to) different distances. Remember the rule: near = thick lens, far = thin lens. Also, hypermetropia = far-sighted, myopia = near-sighted.