In human vision, what does long sightedness (hypermetropia) mean?

Introduction / Context:
Common vision defects include short sightedness and long sightedness. Understanding these conditions is important not only for physics of lenses but also for general health knowledge. Long sightedness is also known as hypermetropia. This question asks you to recall what a long sighted person experiences when looking at near and distant objects.

Given Data / Assumptions:
- Long sightedness is referred to as hypermetropia in medical and physics contexts.
- The question concerns clarity of near versus distant vision.
- We consider the usual case without any corrective lenses in place.
- Short sightedness (myopia) is the opposite condition, where far objects are not clear.

Concept / Approach:
In a normal eye, the lens changes shape to focus images of objects at different distances on the retina. In long sightedness, the eyeball is too short or the eye lens is not strong enough, so light from near objects is not converged sufficiently and the image tends to form behind the retina. As a result, near objects appear blurry, while distant objects may still be focused correctly on the retina and appear reasonably clear. Corrective convex lenses are used in glasses or contact lenses to converge light more before it enters the eye, allowing near objects to be focused properly.

Step-by-Step Solution:
Step 1: Define hypermetropia as a condition where the eye has difficulty focusing on nearby objects. Step 2: Recall that in hypermetropia, the image of a near object would form behind the retina if no correction is used. Step 3: Recognise that distant rays are nearly parallel and require less convergence, so the eye may still focus distant objects well on the retina. Step 4: Conclude that near objects appear blurred, while distant objects can appear clear. Step 5: Compare this with the options and see that option A matches this behaviour. Step 6: Therefore, long sightedness means near images are blurry, while far images remain clearer.

Verification / Alternative check:
People with hypermetropia commonly report difficulty reading small print or doing close work, such as sewing, especially without glasses, while they may see road signs or distant scenery fairly well. Eye doctors prescribe converging lenses for such patients. Physics diagrams of hypermetropic eyes in textbooks show that the image of a near object lies behind the retina and is brought forward by a convex lens so that it falls on the retina.

Why Other Options Are Wrong:
Far images are blurry while near images remain clear: This describes short sightedness or myopia, not long sightedness.
Both near and far images are equally blurry: This could be due to other conditions, but it is not the standard definition of hypermetropia.
There is no blurring at any distance: That would correspond to near normal vision for a given age and is not a defect.

Common Pitfalls:
Learners sometimes reverse the definitions of long sightedness and short sightedness because the terms can be confusing. A simple way to remember is that long sighted people see long distance objects better than near ones. In contrast, short sighted people see near objects clearly and distant objects poorly. Linking these terms to the need for reading glasses or distance glasses can help fix the concepts.

Final Answer:
Long sightedness (hypermetropia) means near images are blurry while distant images remain clear.