Final answer:
Near-sightedness is also known as myopia, where distant objects appear blurry because their images are focused in front of the retina. Myopia is common, affecting about a third of the population and is corrected with diverging lenses.
Step-by-step explanation:
Near-sightedness is also called myopia. This condition affects about one third of people. Individuals with myopia have difficulty seeing distant objects clearly, whereas nearby objects are seen with clarity. This visual defect occurs because the images of distant objects are focused in front of the retina rather than directly on it. The treatment for myopia typically involves the use of diverging lenses to reduce the power of the eye's focus, enabling clear vision at a distance.
Other conditions such as hyperopia or farsightedness, where distant objects are seen more clearly than near ones, astigmatism, which leads to distorted vision, and presbyopia, which generally affects people as they age and makes it hard to see objects up close, are different from myopia and require their respective corrective measures.