When the power of eye lens increases, the defect of vision is produced. The defect is known as

Options

A. shortsightedness
B. longsightness
C. colourblindness
D. None of the above

Explanation

### Step-by-Step Solution:

1. **Understanding the Eye Lens Power**: The power of a lens is defined as the ability of the lens to converge or diverge light rays. It is given by the formula \( P = \frac{1}{f} \), where \( P \) is the power in diopters and \( f \) is the focal length in meters.

2. **Effect of Increased Power**: When the power of the eye lens increases, it indicates that the focal length \( f \) of the lens is decreasing (since power is inversely proportional to focal length). This means that the lens is becoming more converging.

3. **Image Formation**: In a normal eye, light rays coming from distant objects converge on the retina. However, if the power of the lens increases too much, the image of distant objects is formed in front of the retina instead of on it.

4. **Defect of Vision**: The condition where distant objects appear blurry because the image is formed in front of the retina is known as myopia. Myopia is also referred to as short-sightedness.

5. **Corrective Measures**: To correct myopia, a concave lens is used. This lens diverges the light rays before they enter the eye, allowing the image to be formed on the retina.

6. **Conclusion**: Therefore, when the power of the eye lens increases, the defect of vision produced is known as myopia or short-sightedness.

### Final Answer:
The defect is known as **myopia** or **short-sightedness**.

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