Myopia is a refractive defect of the human eye that is also commonly known as which type of sightedness?

Introduction / Context:
Myopia is one of the most common refractive errors of the human eye and frequently appears in entrance and competitive examinations. It affects how clearly a person can see distant objects. Many general knowledge and biology questions ask you to recognise the everyday name for this condition, since laypersons commonly use terms like near sightedness or short sight. Understanding this terminology also helps in basic health awareness and vision care.

Given Data / Assumptions:

• The question states that myopia is a defect of the eye.
• It asks for the common descriptive name for this defect.
• Options include far sightedness, near sightedness, astigmatism, and night blindness.
• We assume basic knowledge of common eye defects and their effects on vision.

Concept / Approach:
In myopia, the eye focuses incoming parallel light rays in front of the retina rather than exactly on it. This usually happens when the eyeball is too long or the refractive power of the cornea or lens is too strong. As a result, distant objects appear blurred, while near objects can be seen clearly without much effort. Because the person can see nearby things better than distant ones, myopia is commonly called near sightedness or short sightedness. In contrast, far sightedness, also known as hypermetropia, is the opposite condition where near vision is more difficult than distance vision.

Step-by-Step Solution:
Step 1: Recall that myopia is associated with difficulty in seeing distant objects clearly. Step 2: Understand that people with myopia can usually read or see objects held close to the eyes without strain. Step 3: Recognise that this pattern of clear near vision and blurred distance vision fits the everyday description of near sightedness. Step 4: Match this description to the correct option that names near sightedness and briefly explains it. Step 5: Confirm that the other options describe different eye problems that do not match myopia.

Verification / Alternative check:
Ophthalmology texts clearly define myopia as a condition where parallel rays from distant objects focus in front of the retina, leading to blurred distance vision. They refer to myopic individuals as near sighted, because they can see close objects more clearly. Myopia is commonly corrected using concave lenses that move the focal point back onto the retina. In contrast, hypermetropia (far sightedness) needs convex lenses. These descriptions confirm that near sightedness is the correct everyday name linked with myopia.

Why Other Options Are Wrong:

• Far sightedness, where distant objects are clear but near objects are blurred: This describes hypermetropia, not myopia.
• Astigmatism, where vision is distorted due to irregular curvature of the cornea or lens: Astigmatism can occur with or without myopia but is a different type of refractive error.
• Night blindness, where vision becomes poor in dim light or darkness: This is usually due to vitamin A deficiency or retinal disorders, not a simple refractive error.

Common Pitfalls:
A frequent confusion is between near sightedness and far sightedness, especially because the names describe what is clear, not what is blurred. Another pitfall is to mix refractive errors with retinal diseases such as night blindness. Remember that myopia is about focusing of light and distance clarity, not about light sensitivity or dark adaptation. Keeping these distinctions in mind will help you quickly select the correct term in similar questions.

Final Answer:
Myopia is commonly known as near sightedness, where near objects are clear but distant objects are blurred.