First of all, the correct option is NOT 'B'. 

A false premise. We cannot explain this answer.


>"Ability of the eye to see objects at all distances is called......"

It is NOT called Myopia.

Myopia is the inability to see far objects.

For your information, the correct answer is Accommodation. 


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11.1.1 Power of Accommodation 

The eye lens is composed of a fibrous, jelly-like material. Its curvature
can be modified to some extent by the ciliary muscles. The change in the
curvature of the eye lens can thus change its focal length. When the
muscles are relaxed, the lens becomes thin. Thus, its focal length
increases. This enables us to see distant objects clearly. When you are
looking at objects closer to the eye, the ciliary muscles contract. This
increases the curvature of the eye lens. The eye lens then becomes thicker. Consequently, the focal length of the eye lens decreases. This enables
us to see nearby objects clearly.

Accommodation:
Accommodation is the ability of the eye to adjust its focus in order to see objects at different distances clearly. It is a process that involves changing the shape of the lens to bring objects into focus on the retina. This adjustment allows the eye to focus on objects that are both near and far.

How Accommodation Works:
Accommodation is primarily controlled by the ciliary muscles located within the eye. When the eye needs to focus on a nearby object, the ciliary muscles contract, causing the lens to become more rounded. This increases the refractive power of the lens, allowing it to bend light rays more sharply so that they converge on the retina. As a result, the nearby object appears clear.

Conversely, when the eye needs to focus on a distant object, the ciliary muscles relax, causing the lens to flatten. This reduces the refractive power of the lens, allowing it to bend light rays less sharply. The light rays then converge on the retina, bringing the distant object into focus.

Importance of Accommodation:
Accommodation is essential for clear vision at all distances. Without accommodation, the eye would be limited to focusing on objects at a fixed distance. This ability to adjust focus is crucial for daily activities such as reading, writing, and driving, as it allows the eye to switch focus between near and distant objects.

Disorders Related to Accommodation:
Two common disorders related to accommodation are myopia and hypermetropia.

- Myopia: Myopia, also known as nearsightedness, is a condition where distant objects appear blurred, while near objects are seen clearly. It occurs when the eyeball is too long or the cornea is too curved, causing light rays to focus in front of the retina instead of on it.

- Hypermetropia: Hypermetropia, also known as farsightedness, is a condition where near objects appear blurred, while distant objects are seen clearly. It occurs when the eyeball is too short or the cornea is too flat, causing light rays to focus behind the retina instead of on it.

Both myopia and hypermetropia can be corrected with the use of corrective lenses, such as glasses or contact lenses, which help to redirect light rays onto the retina for clear vision at all distances.