Question

If you are using eyeglasses of power \( 2D \), your near point is:

• A. \( 25 \) cm
• B. \( 50 \) cm
• C. \( 43 \) cm
• D. \( 32 \) cm

Hint:

Use the formula \( P = \frac{100}{f} \) to find the focal length of corrective lenses.
- The near point with glasses is approximately equal to the focal length of the lens.

Answer 1

The Correct Option is B

The power of a lens is given by: \[ P = \frac{100}{f} \] where: - \( P \) is the power in diopters (D), - \( f \) is the focal length in centimeters. For \( P = 2D \): \[ f = \frac{100}{2} = 50 \text{ cm} \] The near point of a person using glasses is the focal length of the corrective lens. Thus, the correct answer is \(\boxed{50 \text{ cm}}\).